Europe was gearing up for New Year's Eve celebrations on Saturday after Australia kicked off the party with a dazzling fireworks display, with police and event organizers across the globe boosting security in response to recent attacks.
A dazzling fireworks show in Sydney at midnight (1300 GMT) paid tribute to the late stars of 2016 in a light display inspired by David Bowie, Gene Wilder and Prince.
Anna Fassbinder, 18, from Cologne said it took her breath away. "It was incredible, they did things with fireworks I didn't think were possible," she told dpa.
Around 1.5 million people had been expected to pack the Australian city's harbour area to see 7 million Australian dollars' (5.04 million US dollars') worth of fireworks go up in smoke in a 12-minute extravaganza, with 1 billion more viewers expected via live stream on social media.
Police have assured the public there are no known terrorist threats to the festivities, but for the first time buses will be used to block roads leading to the pedestrian zones to prevent truck attacks such as those in Berlin and Nice.
Parties in cities across Germany are set to take place against a backdrop of heavy police presence and bolstered security measures.
In Cologne, where hundreds of women reported being harassed, assaulted and in some cases raped by groups of men during last year's celebrations, authorities had increased the number of police officers on the beat tenfold to around 1,500 in the city centre alone.
Fireworks, a popular New Year's Eve tradition in Germany, were also banned in front of the city's cathedral, were many of last year's attacks took place.
Celebrations in the western city began with a light installation by artist Philipp Geist. Words suggested by Cologne residents in the run-up to New Year's Eve, such as "decency" and "memory," were projected onto the ground and buildings.
Admission to the party at Berlin's Brandenburg Gate, Germany's biggest New Year's Eve celebration, began 10 hours ahead of midnight, allowing time for thorough checks. The event kicks of at 8:15 pm (1915 GMT), with a host of acts performing in the run-up to midnight. Around 1 million people are expected at the event.
In London, armed police officers were deployed for the first time to underground and overground trains in order to ensure a peaceful turn of the year. Five of the British capital's main bridges were shut off and around 3,000 police officers were deployed to the city centre.
Concrete bollards were installed at the Champs-Elysee in Paris, with hundreds of thousands of people expected to join celebrations there. Throughout France, which has been rocked by a series of deadly terrorist attacks in recent years, over 96,000 security forces were deployed to oversee New Year's Eve events.
In contrast to last year, when the new year was overshadowed by the brutal attack of November 13, 2015, which killed 130 people in a night of coordinated violence, Paris was planning a small fireworks display for 2017 from the top of the Arc de Triomphe.
Italy was also on high alert, after the man suspected of ploughing a lorry into a group of people at a Christmas market in Berlin last week was killed in a shootout in Milan. Rome and other major cities are seeing intensified security measures and media reported that fireworks are banned in Turin, Bologna and Venice.
Terrorist threats impacted party plans outside Europe as well, with warnings issued in India and China.
The New York Police Department expects close to 2 million people to converge on Times Square in central Manhattan on Saturday to witness the traditional ball drop.
As in years past, there will be police helicopters overhead and mandatory bag screenings.
But for the first time revellers also will see 65 strategically positioned garbage trucks loaded with sand. The trucks, whose weight of 16 tons doubles with a full load of sand, are "pretty immovable" according to Vito A Turso, a spokesman for the Sanitation Department quoted in the New York Times.
Police commissioner, James P O'Neill, said however that there are no specific threats related to the event on Times Square.
"We're going to have one of the most well policed, best protected events at one of the safest venues in the entire world, given all the assets that we've employed here," O'Neill said.
In addition to the trucks and other security measures, there will be close to 7,000 police officers assigned to guard against crime and terrorism in the city, including any approaches over water or from the air.