Tens of thousands of protesters are gathering in Washington, D.C., for a rally advocating for stricter gun control. Organizers of the "March for Our Lives" rally are hoping to draw 500,000 protesters to the nation's capital on Saturday. The organizers' website says more than 800 "March for Our Lives" events are planned around the world.
The event in Washington began at 12 p.m ET. CBS News is live streaming the event in Washington, and is covering events at other locations.
The protesters, many of them high school students, claim that the youth leadership of this initiative is what will set it apart from previous attempts to enact stronger gun-control legislation.
Over the past five weeks, after the murders of 17 people at the high school, CBS News has followed the students as they started a movement. It's all featured in CBS News' documentary "39 Days." You can watch the one-hour documentary here.
Read a live blog below of updates as they happened during the "March for Our Lives":
Parkland, Florida, becomes center of a movement
7 p.m.: In the 5 1/2 weeks since the massacre in Parkland, Florida, the city has become Ground Zero for gun control activism. An estimated 20,000 people marched through Parkland to the place where, for many, the movement began: Marjory Stoneman Douglas High School.
CBS News correspondent Manuel Bojorquez spoke with survivors of last month's massacre on Saturday.
"As soon as after it happened, and we all got out of the building, it did start a huge movement and change," Emily Quijano said. "A lot of people underestimate us and think we're not as powerful, but this just shows you so many people have listened to us and so many people can support us and we're not just kids."
Paris rallies call for strict U.S. gun control laws
4:09 p.m.: The calls for greater gun control in the U.S. came from across the Atlantic Ocean on Saturday as demonstrators near the Eiffel Tower demanded that U.S. politicians "protect children, not guns!" The protesters in Paris included American and French demonstrators, families and students.
"It's important for Americans even overseas to make sure that Washington knows that we're not pleased with the gun control reform and we want more," said Caitlin Waters, co-organizer of the "March For Our Lives" gathering in Paris.
A letter of support to those affected by the Parkland tragedy was read aloud. Catherine Wilson, who lost her sister Mhairi in the 1996 Dunblane Primary School shootings, was among the speakers.
"I don't understand why the freedom to own a gun is seen as more important than seeing your grandchildren grow up, or feeling safe when you go and watch a film in the cinema," Wilson said.
Sixteen schoolchildren and their teacher were killed in the Dunblane shooting, and the tragedy led the U.K. to enforce strict firearms laws.
Hillary Clinton: "Our future is in the right hands"
3:38 p.m.: Hillary Clinton weighed in on the protests Saturday, praising the young activists who planned the "March for Our Lives" protests.
"Listening to the students from Parkland and across the country today is a reminder of what is possible when our future is in the right hands, and when we match inspiration with determination," the former Secretary of State and Democratic presidential candidate tweeted.
Rubio urges protesters to find common ground with opponents
3:27 p.m.: Sen. Marco Rubio, R-Florida, said in a statement Saturday that he supports protesters' right to march in the demonstrations but urged them to find common ground with opponents.
"While protests are a legitimate way of making a point, in our system of government, making a change requires finding common ground with those who hold opposing views," Rubio said.
Rubio's district includes Marjory Stoneman Douglas High School in Parkland, Florida, where 17 people were killed in a school shooting last month. He said that a ban on bump stocks (used to make guns fire more rapidly), improvements to the gun background check system and other efforts were achieved by finding common ground with those who don't want certain gun bans.
"And finding common ground is what it will take to pass our red flag law so we can take guns away from dangerous people," he added.
Paul McCartney remembers John Lennon at NYC rally
3:09 p.m.: Paul McCartney attended an anti-gun violence rally in New York City and remembered his friend and former bandmate John Lennon. A CNN reporter asked McCartney if he thinks changed can be accomplished with legislation.
"I'm like everyone -- I don't know, but this is what we can do, so I'm here to do it," McCartney said Saturday, while wearing a shirt that read: "We can end gun violence."
"One of my best friends was killed in gun violence right around here, so it's important to me," McCartney said.
Emma González holds moment of silence
2:46 p.m.: Emma González, one of the leading voices of the movement since the Parkland massacre, held a moment of silence at the podium Saturday.
"Since the time that I came out here, it has been 6 minutes and 20 seconds, the shooter has ceased shooting and will soon abandon his rifle and blend in with the students so he can walk free for an hour before arrest," González said, breaking her silence. "Fight for your lives before it is someone else's job."
Brother of Sandy Hook victim: "Enough is enough"
2:38 p.m.: Matthew Soto, a 19-year-old whose sister was killed the Sandy Hook Elementary School shooting, said no change has come in the five years since the shooting in Newtown, Connecticut.
"We do not have to wait for others to make us safe. We must do it ourselves," Soto said.
"To my fellow students. It is our time to stand up. Register to vote. Bring power to the polls. Our lives are not more important than a gun -- that we matter," she added. "Get involved in your community. Change -- no matter how small -- is change."
Obama to protesters: "Keep at it. You're leading us forward"
2:15 p.m.: Former President Barack Obama tweeted Saturday addressing the marches across the country.
"Michelle and I are so inspired by all the young people who made today's marches happen. Keep at it. You're leading us forward. Nothing can stand in the way of millions of voices calling for change," Mr. Obama tweeted.
"We embrace an extremism of love"
2:10 p.m.: Matt Post from Montgomery County, Maryland, told attendees at the Washington march that change won't come easy.
"Our nation's politics are sick with soullessness, but make no mistake, we are the cure," Post said Saturday. "It won't be easy to change things. The immoral, the obstructionists and the complicit are already lining up to block our path. We'll have to have some courage to fix this. It's going to take some will."
11-year-old who lost brother to gun violence: "I would like to not worry about dying"
2:07 p.m.: An 11-year-old from Brooklyn who lost his brother to gun violence spoke during the Washington event Saturday.
"My brother survived for 14 days and died on his 15th birthday, July 10, 2012. At that time, I was only 5-years-old. Senseless gun violence took away my childhood and nothing in my life was ever the same because I no longer have my best friend," Christopher Underwood said. "Losing my brother gave me the courage to be a voice for my generation."
"For me, I would like to not worry about dying, and focus on math and science and playing basketball with my friends. Don't I deserve to grow up?" Underwood asked.
Anti-gun rallies among biggest since Vietnam War
1:53 p.m.: The series of anti-gun protests are shaping up to be one of the biggest youth protests since the era of the Vietnam War, The Associated Press reports. In Washington, throngs jammed Pennsylvania Avenue for blocks. Tens of thousands of teenagers and their supporters roared their approval as survivors of the Parkland, Florida, assault spoke from the stage.
One of them, Delaney Tarr, laid down the students' central demand, a ban on assault-type weapons, and declared "We will continue to fight for our dead friends."
MLK Jr.'s granddaughter: "I have a dream that enough is enough"
1:47 p.m.: Yolanda Renee King, the 9-year-old granddaughter of Martin Luther King Jr. and Coretta Scott King, took the podium Saturday to address the "March for Our Lives" event.
"My grandfather had a dream that his four little children would not be judged by the color of their skin, but by their character. I have a dream that enough is enough, and that this should be a gun free world, period," King said Saturday.
She then led the chant, "Spread the word. Have you heard? All across the nation. We... are going to be. A great generation."
11-year-old speaks on representation
1:39 p.m.: Naomi Wadler, an 11-year-old from Alexandria, Virginia, spoke to thousands about representation at the Washington rally. "I am here to acknowledge and represent the African-American girls whose stories don't make the front page of every national newspaper, whose stories don't lead on the evening news," she said Saturday.
"My friends and I might still be 11, and we might still be in elementary school but we know," she continued. "We also know that we stand in the shadow of the Capitol, and we know that we have seven short years until we too have the right to vote."
Duck from bullets before learning to read
1:30 p.m.: Edna Chavez, a student from South Los Angeles, lost her brother to gun violence. She took the podium in Washington Saturday. "This is normal -- normal to the point that I've learned to duck from bullets before I learned how to read," she said.
"Arming teachers will not work. More security in our schools does not work. Zero tolerance policies do not work," Chavez said. "They make us feel like criminals. We should feel supported and empowered in our schools."
NRA remains silent on Twitter
1:24 p.m.: The National Rifle Association went silent on Twitter Saturday morning, in contrast to its reaction to the nationwide school walkouts against gun violence March 14, when it tweeted a photo of an assault rifle and the message: "I'll control my own guns, thank you."
As of early afternoon, President Trump had not yet acknowledged the demonstrations on Twitter.
Gun-rights supporters rally in Washington
1:22 p.m.: About 30 gun-rights supporters staged a counter-demonstration in front of the FBI headquarters in Washington, D.C., Saturday, standing quietly with signs such as "Armed Victims Live Longer" and "Stop Violating Civil Rights."
David Hogg: "Let's put the USA over the NRA"
1:20 p.m.: David Hogg, a student at Marjory Stoneman Douglas High School, took the podium in Washington and said protesters are "going to make this the voting issue." We're going to take this to every election in every state."
"We're going to make sure the best people get in our elections to run not as politicians, but as Americans. Because this -- this -- is not cutting it," Hogg said Saturday.
"When people try to suppress your vote and stand in front of you because you're young, we say, 'no more,'" Hogg continued. "They will try to separate us by race and class -- they will fail. We will come together."
He added, "Let's put the USA over the NRA."
Pro-gun rally in Salt Lake City
1:11 p.m.: A pro-gun rally is taking place Saturday in Salt Lake City. CBS affiliate KUTV reports gun rights advocates have arrived at the Utah State Capitol. They chanted "freedom!" as they marched.
The rally is called "March Before Our Lives" -- a counter-protest to the rally pressing for gun legislation. KUTV reports Utah Gun Exchange is holding the counter-rally.
"Are they going to arm our pastors, ministers and rabbis?"
1:06 p.m.: Alex Wind, a survivor of the Parkland, Florida, high school shooting, gave a powerful speech at Saturday's rally in Washington.
"If teachers start packing heat, are they going to arm our pastors, ministers and rabbis? Are they gonna arm the guy scanning tickets at the movie theater? Are they going to arm the person wearing the Mickey Mouse costume at Disney? This is what the National Rifle Association wants and we will not stand for it."
"We would not need metal detectors, clear backpacks and more weapons in our streets if there weren't weapons of war in the hands of civilians!" Wind said Saturday.
Counter-protesters march at Boston rally
12:40 p.m.: Thousands of people are marching to Boston Common on Saturday during the "March for Our Lives" gun control rally. When the group arrives, they'll be met by a small counter protest, CBS Boston reports. The group of counter-protesters began in the morning on the steps of the State House and moved onto Boston Common. There are about 100 counter protesters.
Counter-protesters and opposing activists shouted at one another. Police stepped in between the groups to keep the peace.
When the counter-protesters moved to Boston Common, police officers on bicycles formed a perimeter around them to prevent any potential clashes.It was not clear what group the counter-protesters are supporting.
"The voters are coming," shooting survivor says
12:30 p.m.: Cameron Kasky, a student at Marjory Stoneman Douglas High School who survived last month's massacre, spoke at Saturday's rally. Kasky said that politicians need to "represent the people or get out."
"Shooting after shooting, the American people now see one thing they all have in common: the weapons. Politicians, either represent the people or get out. The people demand a law banning the sale of assault weapons. The people demand that we prohibit the sale of high-capacity magazines. The people demand universal background checks. Stand for us or beware, the voters are coming," Kasky said.
Houston mayor: Adults have a responsibility to protect children
12:27 p.m.: The mayor of Houston, Texas, told thousands of demonstrators at a "March for Our Lives" rally that adults have a responsibility to protect all children. Mayor Sylvester Turner spoke at the Tranquility Park event Saturday morning.
"We have a responsibility for those of us as adults, we have a responsibility to stand up and protect our children," said Turner.
Turner also chanted with the crowd "Now is the time" to "do the right thing."
Student protester asks: "Are we next?"
12:19 p.m.: CBS News correspondent Adriana Diaz reports that students from across the country traveled to Washington for Sunday's march. Diaz spoke two sisters who traveled to the event from New Jersey.
"We decided to come because we're just sick and tired of waking up everyday scared to go to school. Students should definitely not have to feel that way and have that thought in the back of their head. We're just sick of all these shootings happening and thinking, like, 'are we next?'" one student told Diaz.
D.C. restaurants offer free food to protesters
Several restaurants in Washington, D.C., are providing free food to protesters participating in the rallies Saturday. CBS affiliate WUSA-TV reports the movement -- titled "Food for Our Lives" -- features local businesses offering free and discounted meals throughout the day.
"We proudly stand with the students who have come to make their voices heard against gun violence," the organizers wrote on their website.
With a valid ID, students under 18 can eat for free at The Pig, The Bird and Think Food Lab.
Students can also get half-priced meals at Beefsteak, Shake Shack, Sugar Shack Donuts, Sweetgreen, Cava, Rasa, Taco Bamba, Protein Bar, Matchbox and Buredo.
Students chant "enough is enough"
11:20 a.m.: Students chanted "enough is enough" and held up signs with slogans like "our ballots will stop bullets" at a rally in Parkland, Florida, where 17 people were killed in a school shooting last month.
More than 20,000 people filled the park near Marjory Stoneman Douglas High School for the March for Our Lives rally Saturday morning. Others from the area traveled to Washington, D.C., where the main March for Our Lives event is being held.
New England Patriots owner Robert Kraft let over 100 people, including families of victims of the Parkland shooting, use the team's charter plane for the trip. Team spokesman Stacey James says astronaut Mark Kelly reached out to Kraft for the favor. "It's a hard thing to say no to, especially involving these victims," James said.
20,000 expected at Florida anti-gun protest
11 a.m.: More than 20,000 people are expected at the March for Our Lives rally nearest the Florida school where last month's deadly shooting occurred. Police presence was heavy early Saturday at a park near Marjory Stoneman Douglas High as organizers set up and demonstrators streamed in.
Eighteen-year-old Sabrine Brismeur and 17-year-old Eden Kinlock came from schools 20 miles away to pass out water. Kinlock said that may seem "like a small thing but it helps in the bigger picture."
White House releases statement on march
10:30 a.m. ET: "We applaud the many courageous young Americans exercising their First Amendment rights today," White House Deputy Press Secretary Lindsay Walters said in a statement.
"Keeping our children safe is a top priority of the President's, which is why he urged Congress to pass the Fix NICS and STOP School Violence Acts, and signed them into law," the statement says. "Additionally, on Friday, the Department of Justice issued the rule to ban bump stocks following through on the President's commitment to ban devices that turn legal weapons into illegal machine guns."
Rally outside U.S. Embassy in London
9:30 a.m. ET: Dozens of protesters are rallying outside the U.S. Embassy in London in solidarity with the "March for Our Lives" protest against gun violence. Students, families with children and other protesters raised placards reading "Protect kids not guns," ''Never again," and "Enough is enough" Saturday outside the new embassy building in south London.
Amnesty International U.K.'s director Kate Allen referred to the 1996 school killings at Dunblane Primary School in Scotland, in which 16 students and a teacher were killed.
"After our own school shooting at Dunblane, new gun ownership laws were introduced in Britain and that's exactly what's needed in the United States, where gun deaths are a national tragedy," she said.