In Bangkok, police-flanked partygoers rang in the new year at the site of a deadly bombing that took place just months ago. In Paris, residents recovering from their city's own deadly attacks will enjoy scaled-back celebrations. And in Belgium's capital, authorities anxious after thwarting what they say was a holiday terror plot have canceled festivities altogether.
As the final hours of 2015 draw to a close, many are bidding a weary and wary adieu to a year marred by attacks that left nations reeling and nerves rattled.
Still, most places are forging ahead with their celebrations as many refuse to let jitters ruin the joy of the holiday.
"We still have this fear but we need to continue to live," said Parisian Myriam Oukik. "We will celebrate."
A look at how people around the world are doing exactly that:
New Year's Eve is Japan's biggest holiday, and millions crammed into trains to flee the cities for their hometowns to slurp down bowls of noodles, symbolizing longevity, while watching the annual "Red and White" song competition on television. As midnight approached, families bundled up for visits to neighborhood temples, where the ritual ringing of huge bronze bells reverberated through the chill.
Tokyo is on special alert for security issues this year, with posters in subways and other public spaces warning people to keep their eyes open for suspicious packages or activities.
South Koreans marked New Year's Eve with traditional bell ringing ceremonies, fireworks and outdoor music and dance performances. Thousands of people, including North Korean refugees, were expected to gather at a town near the border with rival North Korea to watch one of the ceremonies and wish for peaceful Korean unification.
North Korea was expected to mark the new year with a speech by leader Kim Jong Un, which outside observers pore over for insight into the reclusive country's policy directions.
New Zealand, the first nation with a sizable population to celebrate the New Year, counted down the seconds to midnight with a giant digital clock on Auckland's landmark Sky Tower. Horns blared and crowds cheered as the tower was lit up with fireworks, with colors shifting from green to red to white.
Simultaneous fireworks displays erupted along Sydney's famed harbor, where people crowded onto balconies, into waterside parks and onto boats as they jockeyed for the best view, clinking glasses and whooping with joy as the first pyrotechnics exploded.
More than 1 million people were expected to watch the glittery display, featuring a multicolored firework "waterfall" cascading off the Harbour Bridge and effects in the shapes of butterflies, octopuses and flowers.
Australian officials, struggling to contain the threat from home-grown extremists, encouraged revelers to enjoy the evening and assured them that thousands of extra police were patrolling major cities.
"Don't change your way of life," Melbourne Lord Mayor Robert Doyle urged residents of his city. "Don't let events from around the world challenge the way that we live."
An official New Year's Eve celebration was staged near Beijing's Forbidden City with performances and fireworks, and one of China's most popular TV stations broadcast a gala from the National Stadium, known to most as the iconic Bird's Nest.
For safety reasons, Shanghai closed subways near the scenic waterfront Bund because of a stampede last New Year's Eve that killed 36 people and blemished the image of China's most prosperous metropolis.
Beijing's shopping and bar areas are under a holiday security alert that started before Christmas and has resulted in armed police standing guard at popular commercial areas. Police commonly issue such alerts during holiday periods.
Security was beefed up in Malaysia's biggest city, Kuala Lumpur, where fireworks greeted the new year at a historic square as well as at the Petronas Twin Towers, one of the world's tallest buildings.
Malaysian authorities have detained more than 150 suspects linked to the Islamic State of Iraq and Syria (ISIS) over the past two years, including some who were allegedly plotting to launch attacks in strategic areas of Kuala Lumpur.
No specific threats timed for New Year's revelries were detected in the capital, Manila, or other major cities, although government forces are always on alert due to the presence of small but violent Muslim militant groups in the country's south.
Concern on New Year's Eve was instead focused on the use of illegal fireworks, which last year injured more than 850 people. Shopping malls and cities organized fireworks displays to discourage people from lighting their own firecrackers. A huge religious sect, the Iglesia ni Cristo, was to attempt to break the world record for the largest fireworks display and the highest number of sparklers to be lit in one place.
An annual procession of the Black Nazarene, a black wooden statue of Jesus Christ, was held a day earlier than usual Thursday to prevent injuries from mounds of trash and unexploded firecrackers that litter Manila's streets after New Year's revelries. A larger procession of the statue will be held Jan. 9.
Less than six months after a pipe bomb killed 20 people at the Erawan Shrine in Bangkok, tens of thousands rang in the new year at the same intersection with live music and a countdown.
Up to 5,000 police were in the area, with explosive ordnance disposal experts sweeping the area ahead of time.
Noisier still were the celebration along the Chao Phraya River, where tourism officials planned spectacular fireworks over two of the kingdom's most iconic landmarks, the Grand Palace and Wat Arun -- the Temple of Dawn.
Indonesia is on high alert after authorities said last week that they had foiled a plot by Islamic militants to attack government officials, foreigners and others. About 150,000 police officers and soldiers have been deployed to safeguard churches, airports and other public places.
National Police spokesman Maj. Gen. Anton Charliyan said security is focused on anticipating attacks in vulnerable regions including the capital, Jakarta, the tourist resort of Bali and restive West Papua, where President Joko Widodo is celebrating the new year.
More than 9,000 police are deployed in Bali, the site of Indonesia's deadliest terror attack, which killed 202 people in 2002.
Hotels and restaurants in and around New Delhi have been advertising grand party plans with live bands, dancing and plenty of drinks.
With security a concern, police and anti-terrorism squads on Tuesday conducted drills at a crowded shopping mall and food court. Witnesses, however, were unimpressed. Mona Arthur, a Delhi journalist who was in the mall at the time, dubbed the exercise a "mockery of a mock drill."
She and a friend were shopping when two police officers ran past them. Then a security official said two terrorists had entered the mall.
"The whole thing was comical," said Arthur, who was irritated that no information was given to shoppers on where to go or what to do.
UNITED ARAB EMIRATES
In the megacity of Dubai, a massive fire broke out two hours before midnight in the 63-story The Address hotel more than two hours before midnight, in the area where a massive fireworks display was being prepared.
The five-star hotel is near the Burj Khalifa, the world's tallest building at 905 yards. At least one person suffered a heart attack from the smoke and over-crowding during evacuation late Thursday, and 14 reportedly suffered minor injuries.
Organizers say the Burj Khalifa had been fitted with 400,000 LED lights and 1.6 tons of fireworks will be used in the display.
Burning debris rained down from the building as firetrucks raced to the scene. It was not immediately clear what caused the fire, which ran up the 63-story building. The Address Downtown Dubai is a 991 foot-tall skyscraper that has 626 luxury apartments and 196 hotel rooms, according to Skyscraper Center, which tracks skyscrapers.
Nada Fayez, 46, a mother of four teenagers, planned to celebrate the new year at home with her family. She said the security situation in Jordan is stable and she would have no concerns if her sons and daughter preferred to go out for celebrations.
Jordan has taken a high-profile role in the U.S.-led military campaign against ISIS, which controls large areas of neighboring Syria and Iraq.
Security has been beefed up in the streets of Amman, as well as in malls and hotels.
Gaza's Islamist Hamas rulers banned new year celebrations in the Palestinian coastal enclave. Police spokesman Ayman Batniji said hotels and restaurants were allowed to hold parties a day earlier, or a day later.
"Celebrating the new year contradicts the instructions of Islamic religion," Batniji said. "It's a Western custom that we don't accept in Gaza."
The militant Hamas group wrested control of Gaza, home to 1.8 million people, from forces loyal to Palestinian President Mahmoud Abbas of the secular Fatah movement in 2007.
Police in Kenya, which has been repeatedly attacked by al-Shabaab militants based in neighboring Somalia, are urging vigilance as many people prepare to celebrate in hotels and watch midnight fireworks displays. Unauthorized fireworks have been banned as a safety hazard "in view of the elevated threat of terrorism," police said.
"Kenyans should remain vigilant at all times and know that we are facing a real terror threat since the split of al-Shabaab into two groups, one supporting al Qaeda and another Islamic State," Inspector General of Police Joseph Boinnet told The Associated Press. "We are facing a real terror threat because these two groups are struggling to outsmart each other. This therefore is not a time to drop our guard, particularly during this festive season."
The French are still recovering from the Nov. 13 attacks that left 130 people dead in Paris, and authorities prepared for a possible worst-case scenario on New Year's Eve. About 60,000 police officers and troops were deployed across the country, and revelers said that made them feel safer.
"The same troops who used to be in Mali, Chad, French Guyana or the Central African Republic are now ensuring the protection of French people," said Defense Minister Jean-Yves Le Drian.
France's year of trials started with attacks on satirical newspaper Charlie Hebdo Jan. 7 and on a Paris kosher market two days later, violence that killed 17 people plus the three Islamic extremist attackers.
In the ensuing months, attacks were thwarted on a church and a high-speed international train, and another Islamic extremist decapitated his boss at an American-owned chemical plant.
French president Francois Hollande used his traditional New Year's Eve speech to warn that the terrorist threat is still at its "highest level" in France.
"2015 has been a year of suffering and resistance," he said. "Let's make 2016 a year of courage and hope."
Paris canceled its usual fireworks display in favor of a five-minute video performance at the Arc de Triomphe just before midnight, relayed on screens along the Champs Elysee, where people chanted.
Paris Mayor Anne Hidalgo said the show was aimed at "sending the world the message that Paris is standing, proud of its lifestyle and living together."
"It was a very strange year and we just want 2016 to be different, simply a normal one," said Parisian Francoise Malterre. "It does not need to be an excellent one, but just a normal one."
In Brussels, 2016 was rung in without the customary fireworks display and downtown street party. The festivities were canceled by Mayor Yvan Mayeur, who said Wednesday evening it would have been impossible to administer adequate security checks to all of the 100,000 people expected to attend.
Earlier this week, Belgian authorities announced they had arrested two men suspected of planning to stage attacks in Brussels over the holidays. On Thursday, six more people were brought in for questioning; three were released as night fell.
A total of 10 people have also been detained in Belgium for suspicion of involvement in the attacks that killed 130 people in Paris on Nov. 13.
The Federal Prosecutor's Office also said six people were brought in for questioning Thursday morning in connection with a suspected plot to stage extremist attacks, but at least three were released as night fell.
On Thursday morning, forklifts and trucks removed generators and other equipment from the Place de Brouckere, the broad square in central Brussels where the fireworks show was supposed to happen. Some people said they understood the cancellation, others called it knuckling under to the extremist threat.
Rainy weather dampened the New Year celebrations in Berlin, where security was tighter than in previous years. Several hundred thousand people still turned out for several minutes of fireworks at the Brandenburg Gate, wishing each other "Froehes neues Jahr" and expressing their hopes for a peaceful 2016.
In Munich, police warned about an hour before the New Year of a "serious, imminent threat" of a terror attack. Despite the call by police for people to stay away from crowds, thousands of people were still on the streets to meet the new year with fireworks.
Several hours after the alert in Munich, two train stations were reopened and police said the threat had not been substantiated.
Major celebrations marked by fireworks spectaculars went off without a hitch in London, Edinburgh and other big cities despite a terror threat judged to be "severe." Scotland Yard planned a major deployment of roughly 3,000 officers in central London, including hundreds of specially trained and equipped firearms officers. Police said "all available staff" will be called on to protect people at the festivities.
Police advised revelers not to come to the fireworks display in central London without a ticket and to be ready to have their belongings searched.
Police have thwarted a number of attacks this year as a tiny but increasing number of British Muslims have endorsed the cause of ISIS extremists.
Rio de Janeiro's main soiree on Copacabana Beach will have dual themes: the 100th anniversary of samba music and the kickoff to the Olympics, which the city will host in August. More than 2 million people are expected on the beaches Thursday.
Police say more officers will be on hand this year than the 1,600 deployed for last year's bash. Capt. Ivan Blaz, spokesman for Rio's police force, told The Associated Press that they have received no reports of extremist threats.
The partying will happen at a time when Brazil is mired in crisis. The economy has plunged, the opposition is pushing to impeach President Dilma Rousseff and a host of financial and government scandals have soured Brazilians.
Around 1 million people converged on New York City's Times Square for the annual celebration. The party began with musical acts, including Luke Bryan, Charlie Puth, Demi Lovato and Carrie Underwood, and ended with fireworks and the descent of a glittering crystal ball from a rooftop flagpole.
This year's festivities were protected by about 6,000 New York City police officers, including members of a specialized counterterrorism unit.
Officials are urging revelers to leave bags, backpacks and strollers at home as police ready for hundreds of thousands of partiers to flood the Las Vegas Strip. It's not a first-of-its-kind request, but it's getting extra emphasis following deadly attacks in Paris and San Bernardino and, more recently, a driver in Las Vegas who witnesses say intentionally plowed into pedestrians, killing one person.
Nearly 1,000 uniformed officers and an undisclosed number of undercover officers will be posted along the popular four-mile-long, casino-filled corridor.
Las Vegas Mayor Carolyn Goodman lamented the prospect that fear might keep people from celebrating New Year's Eve, or any event.
"It can't be. We cannot let that rule," she said.