PARIS (CBSNewYork/AP) -- The NYPD was on high alert Friday night with visibly increased security, and the U.S. State Department issued a global travel warning, the night after security forces ended a three-day terror rampage around Paris by killing the brothers who staged it.
The State Department issued a global travel warning after the attacks in Paris, as well as the incidents in Sydney and Ottawa. The State Department warning said attacks against Americans are becoming increasingly prevalent, and also cites an increased risk of reprisals against U.S. and Western targets for the U.S.-led intervention against ISIS militants in Syria and Iraq.
In all, seven people were killed Friday -- three terrorists and at least four hostages -- two days after 12 people were massacred in the Charlie Hebdo attack.
Those killed included brothers Said and Cherif Kouachi, who attacked the Charlie Hebdo satirical newspaper in Paris on Wednesday, and Amedy Coulibaly, an associate who seized a kosher supermarket to try to help them escape.
As CBS2's Weijia Jiang reported, police were in place and on the prowl following the grisly attacks.
"The NYPD went into high alert immediately after learning about the attack and hostage situation, and has been in touch with the NYPD Intelligence Bureau Detective assigned to the liaison post in Paris," Mayor Bill de Blasio said in a statement continued. "The NYPD will maintain vigilant at relevant sites across New York City, including high profile Jewish and French sites, and is committed as always to the full safety and protection of all New Yorkers."
The mayor expressed grief for those affected by the attacks, and denounced the terrorist acts.
"I condemn in the strongest of terms the shocking acts of terrorism and anti-Semitism we saw earlier today in France, in which a kosher supermarket was targeted during the pre-Shabbat rush. My thoughts and prayers are with the families of the victims and the people of France during this difficult week," the mayor said in the statement.
As CBS2's Tony Aiello reported Friday afternoon, the terror group al-Qaeda in Yemen has taken credit for the violence in France throughout the week, which ended with the decisive police action that left the perpetrators dead.
Sixteen hostages were freed on Friday, one from a printing plant and 15 from the grocery store.
Paris shut down a famed Jewish neighborhood amid fears that a wider terror cell might launch further attacks.
Said and Cherif Kouachi came out with their guns blazing Friday evening after an all-day hostage siege at a printing plant in Dammartin-en-Goele northeast of Paris, a French police official said.
Heavily-armed police had stormed into the print shop around 5 p.m. France time. Friday afternoon, explosions and gunshots rang out and white smoke rose outside as a police SWAT team clambered onto the roof.
The Kouachi brothers were killed in the shootout and their hostage was freed, authorities said.
During the standoff before the shootout, a French journalist called the print shop and spoke to younger brother Cherif Kouachi.
"We are just telling you that we are the defenders of prophet Muhammad," he said. "I was sent -- me, Cherif Kouachi -- by al-Qaeda in Yemen. I went there, and Sheikh Anwar Al-Awlaki financed my trip."
Al-Awlaki was the American-born terror leader killed in a U.S. drone strike in 2011.
Meanwhile, an accomplice, Amedy Coulibaly, took at least five hostages Friday afternoon at a kosher grocery in Paris then died in a nearly simultaneous raid there, said Gael Fabiano of the UNSA police union. He had threatened to kill the hostages unless the Kouachi brothers were allowed to flee, authorities said.
Several people were rescued from the Porte de Vincennes grocery store. Police said at least four hostages there were killed, while several others – including a man with a child – escaped.
Police also believe Coulibaly murdered a female police officer in a suburb just south of Paris on Thursday morning. Coulibaly had been a co-suspect with Cherif Kouachi in a court case involving terrorism that never made it to trial.
French President François Hollande said Coulibaly's choice of a kosher market was "an anti-Semitic act."
Meanwhile in New York, terror expert Peter Romaniuk of CUNY John Jay College praised the decisive action to end the standoffs.
"I'm sure they were looking at the clock. I'm sure they were eager to bring the situation to an end," Romaniuk said. "I think it's very important, as a deterrent to future would-be hostage takers, that they should consider that future hostage situations are dealt with promptly and very efficiently, and indeed that seems to have been the case."
France has been on high alert since the massacre Wednesday at Charlie Hebdo. Eight journalists, two police officers, a maintenance worker and a visitor were killed in the newspaper attack, including the paper's editor.
The satirical paper had long drawn threats for its depictions of Islam, although it also satirized other religions and political figures. It had caricatured the Prophet Muhammad and a sketch of Islamic State's leader was the last tweet sent out by the irreverent newspaper, minutes before the attack.
Cherif and Said Kouachi were named as the chief suspects after Said's identity card was left behind in their abandoned getaway car. Prime Minister Manuel Valls has said both suspects had been known to intelligence services before the attack.
The Kouachi brothers led police on a chase around northeast France, robbing a gas station Thursday and stealing a car Friday morning before seizing the hostages at the printing plant.
Police were still searching late Friday for Hayet Boumddiene, described as Coulibaly's wife. They had good intelligence about what was happening there, by tapping into the market's security cameras.
Another suspect, 18-year-old Mourad Hamyd, surrendered at a police station Wednesday evening after hearing his name linked to the attacks. His relationship to the Kouachi brothers was unclear.
Cherif Kouachi was convicted of terrorism charges in 2008 for ties to a network sending jihadis to fight U.S. forces in Iraq.
A Yemeni security official said his 34-year-old brother, Said Kouachi, is suspected of having fought for al Qaeda in Yemen. Another senior security official said Said was in Yemen until 2012.
Both officials spoke to The Associated Press on condition of anonymity because of an ongoing investigation into Kouachi's stay in Yemen. A U.S. official said both brothers were on the American no-fly list.
Both al-Qaeda and the Islamic State group have repeatedly threatened to attack France, which is conducting airstrikes against extremists in Iraq and fighting Islamic militants in Africa.
Late Friday, French authorities were asking for vigilance, fearing other attacks may be pending.
Meanwhile, John Miller, the NYPD's deputy commissioner of intelligence and counterterrorism, said earlier this week that a detective assigned to Paris has been relaying information, allowing police in New York to monitor developments.
Long Island Rep. Peter King (R-N.Y.), who chairs the House subcommittee of counterterrorism and intelligence, said there is no evidence of credible threats against the U.S., but said "we are still very much on guard."
"It appears, the evidence so far, is that this was somehow affiliated with al Qaeda in the Arabian Peninsula. That's the group that operates out of Yemen and they have made it a point over the years that they want to attack the United States," King told WCBS 880.
Many here at home watched the events in France, especially the hostage situation in the kosher market, as they unfolded Friday.
"It's disturbing but unfortunately it's a concern of the Jewish population that's living there," one man at a Jewish market in the Riverdale section of the Bronx told 1010 WINS' Al Jones.
New Yorkers Monitor Events In France
Malcolm Hoenlein, executive vice-chairmen of the Conference of Presidents of Major American Jewish Organizations, said Friday's market attack wasn't the first against Jews in Paris.
"It's unfortunately become too commonplace, too tolerated and despite the good words of French officials and the efforts of French police, it's far from sufficient," he told 1010 WINS.
The attacks in France have also created concerns about copycats at iconic locations in New York City. CBS2's Marcia Kramer will have more on that story coming up tonight at 6 p.m.
Check Out These Other Stories From CBSNewYork.com:
(TM and © Copyright 2015 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2015 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)
for more features.