Australia rang in the new year Sunday with a spectacular fireworks display in Sydney, sending rainbow-colored showers into the night sky and defying the global terror attacks that cast a pall over 2016.

Around 1.5 million people packed Australia's biggest city to watch as the midnight fireworks erupted from Sydney Harbour Bridge, with the extravaganza beamed to television sets and phones across the world.

The visual feast paid tribute to some of the international musical legends who died this year, including David Bowie and Prince, with purple rain pouring off the bridge in an early display and firework "stars" soaring high above the harbour.

2016 has seen repeated bloodshed, most recently a deadly truck attack at a Berlin Christmas market, a similar incident on Bastille Day in France that killed 86, and atrocities in Turkey and the Middle East.

But the New South Wales state premier urged "business as usual", as a larger-than-usual crowd gathered due to the weekend timing and warm weather.

"My encouragement to everyone is to enjoy New Year's Eve... in the knowledge that police are doing everything they can to keep us safe," Premier Mike Baird said.

Around 2,000 extra officers have been deployed in Sydney after a man was arrested for allegedly making online threats against the celebrations.

There were a number of other reported threats this holiday period, in Asia-Pacific and elsewhere.

In Melbourne, police foiled a "significant" Daesh-inspired Christmas Day terror plot.

Indonesia said it foiled plans by an Daesh-linked group for a Christmas-time suicide bombing, and 52 died in the Philippines in bomb attacks blamed on Islamist militants.

Israel on Friday issued a warning of imminent "terrorist attacks" to tourists and western targets in India.

Despite the terror fears, revelers in Hong Kong and Taipei were expected to throng city streets to watch firework performances.

In Japan, shoppers filled markets to buy tuna and crabs — seen as expensive items for special feasts — for New Year's Day family gatherings.