People around the world joyfully welcomed the start of 2015 in an international celebration that was marred by a tragic incident in Shanghai.
At least 35 people were killed in a stampede in China's largest city just before midnight in an area near the riverfront, with dozens of others being injured.
The cause of the stampede is being investigated by officials, who last week canceled a laser show at the same site to avoid large crowds from gathering.
Some said the incident was at least partly caused by a restaurant that threw fake money off the upper floor of a building, causing people to rush for it and to knock others down, who were then trampled by the crowd.
Others said crowds of people were trying to get onto a platform on the Huangpu River.
Chinese President Xi Jinping called for a thorough probe of the tragedy and ordered local and regional governments across the country to ensure a similar incident could not be repeated.
A somber mood also was felt in Malaysia with the crash of the AirAsia passenger plane on December 28 -- the third Malaysian-based airliner to end in tragedy in 2014 -- and flooding in the northeast of the country that has displaced some 250,000 people.
In the Iraqi capital, officials ordered a one-night lifting of the overnight curfew that has been in effect for than a decade to allow Baghdad's citizens to stay out late and celebrate the new year.
But streets in Baghdad's commercial districts were closed as a precaution against suicide bombings by Islamist militants, which have plagued the city for months.
Elsewhere on December 31, more than 1 million people converged on Sydney's harbor in Australia for its famous fireworks display near the opera house.
In the United Arab Emirates, hundreds of thousands watched what is considered the world's biggest fireworks and laser shows on and around the world's tallest building, the Burj Khalifa.
And tens of thousands braved subzero temperatures on Moscow's Red Square for a more modest fireworks show that illuminated the famous St. Basil's Cathedral and Lenin's mausoleum.
Later, people gathered at Berlin's Brandenburg Gate for festivities that included an open-air concert and celebrations marking the 25th anniversary of the fall of the Berlin Wall.
In Paris, an animated laser and light show was projected onto the Arc de Triomphe as thousands of people marked the start of 2015 by overflowing the famous Champs d'Elysees boulevard.
Hundreds of thousands of people gathered in central Hong Kong to watch a pyrotechnic show near the bay, just weeks after officials tore down tents and dispersed pro-democracy protesters who had camped out in the streets for weeks.
In Spain, hundreds of thousands of revellers came to Madrid's Puerta del Sol, while in Barcelona a massive fireworks display was held for tens of thousands.
The English capital staged a New Year's Eve fireworks show along the River Thames and the Scottish capital of Edinburgh held its traditional street party known as Hogmanay.
In Japan, large boxes were set up outside the Meiji Jingu Shrine in Tokyo for traditional Shinto worshippers to leave their offerings in hopes of having a successful new year.