Sydney extravaganza kicks off global New Year parties

SYDNEY, Australia (UPDATED) – Australia rang in the New Year Sunday with a spectacular display of rainbow-colored fireworks cascading from Sydney Harbour Bridge, as revelers marked the nation's legalization of gay marriage amid tight security.

About 1.5 million people packed the city’s foreshore to watch the pyrotechnics light up the sky above the historic bridge and the iconic opera house, the first major celebrations worldwide after New Zealand.

"This is a fabulous way to see out 2017 – the year that 4 out of 5 Sydneysiders said a resounding 'Yes' to marriage equality," said Sydney Lord Mayor Clover Moore of the nationwide postal vote in support of change.

Thousands turned out earlier in New Zealand's largest city Auckland for the annual New Year's Eve street party, marked by a major fireworks display from the Sky Tower.

Around the world

Celebrations then move across the world to Asia, the Middle East, Africa, Europe and finally the Americas.

Dazzling light shows will bid farewell to 2017.

Toughest security in years

Stricter security will be a key focus amid fears that the huge crowds in public places could be targets for vehicle and other terror attacks. 

In Australia, the stronger police presence will include some officers carrying semi-automatic rifles in Sydney and bollards used as barriers against vehicles.

Earlier in December one man was killed and more than a dozen hurt when a man plowed a car into a crowd of pedestrians in Melbourne.

"You're going to see more police than ever out, it will be our largest contingent... (given) the current security environment," said Victoria state police acting chief commissioner Shane Patton.

Other cities are also preparing for possible threats following deadly vehicle assaults over the past two years in Barcelona, Nice and London.

New York's Times Square celebrations will be guarded by the strongest security presence in years, after two recent attacks apparently inspired by the Islamic State group.

IS's defeat in Iraq and Syria was one of the key stories this year, although the jihadists remain a threat and numerous attacks around the world were claimed by them or Al-Qaeda-linked groups.

Donald Trump has stolen the spotlight as he made his debut as US President in 2017, with "America first" policies and a bombastic personal style that has shaken up international diplomacy. 

The former reality television star is likely to continue dominating headlines in 2018, with escalating tensions over North Korea among a host of global challenges in the new year.

Other political and diplomatic earthquakes set to rumble into 2018 include the crisis in the Middle East between Saudi Arabia and its allies against Qatar, and the humanitarian disaster in Yemen.

In Europe, further talks on Brexit will help shape the region's future trade relationship while Russia is set to host the football World Cup amid frictions with the West. –