|Tens of thousands gathered to watch a spectacular fireworks show launched from Sky Tower in Auckland, New Zealand
Countries in the south-Pacific region have become the first to celebrate New Year's day, as the rest of world prepares for the approaching event.
The tiny island nation of Kiribati was the first to welcome in 2011 at 1000GMT on Saturday. The deeply religious community of about 6,000 had been set to mark the occasion with village church services.
New Zealand, at 1100GMT, and just two hours later Australia kicked off celebrations with an extravagant display of fireworks.
When the clock struck midnight in Auckland, New Zealand's biggest city, fireworks were launched from atop the 328 metres high Sky Tower, the world's 15th tallest structure. Tens of thousands gathered around Auckland Harbour to watch the spectacular display which could be seen from across the city.
In Sydney, Australia's capital, about 1.5 million people crammed around Sydney's Harbour to see a spectacular fireworks show.
Sydney touted its claim to be the New Year's Eve capital of the world with a spectacular display over the iconic Harbour Bridge using 7 tons of fireworks, its largest since 2000. Luxury yachts and smaller boats filled the harbour, while others filled pubs, clubs and balconies with a view of the show.
New Year's day comes as the world experiences extreme weather conditions, including heat waves and floods in the south Pacific.
Extreme, 43 degrees Celsius heat brought the risk of wildfires near the southern Australian city of Adelaide, while celebrations in the country's north were muted by floods that left vast swathes of land underwater and forced thousands to leave their homes.
New Zealand, which has experienced a mild heatwave over the festive period, moved into 2011 just an hour after Kiribati with celebrations themed "Hot in the City".
In the southern New Zealand city of Christchurch, thousands celebrated despite a minor 3.3 earthquake that struck just hours before midnight. The city has rumbled with many aftershocks from a powerful 7.1 magnitude earthquake that damaged buildings across the city on Sept. 4.
Officials approved celebrations only after late checks and modifications, including removing the city cathedral's crucifix in case it fell on revellers.