Sydney has welcomed the New Year with a message of peace following the Bondi Beach mass shooting, as huge crowds gathered to watch the city's annual fireworks display.

The words peace and unity were projected onto the Sydney Harbour Bridge, as thousands of heavily armed police officers patrolled the streets - a rare and stark sight in Australia - as part of heightened security measures.

New South Wales (NSW) Police said more than 2,500 officers were on duty across the city, and some officers were authorised to carry high-grade weapons.

The attack on 14 December targeted Australia's Jewish community and killed 15 people at a Hanukkah festival.

The Sydney Harbour Bridge was lit up by a white light to symbolise peace, and a Jewish menorah was projected on to the pylons of the bridge to show solidarity with the Jewish community.

Official New Year's Eve parties were paused at 23:00 local time (12:00 GMT) for a minute's silence to commemorate the victims of the attack.

Pictures from Sydney Harbour - where thousands gather every year to watch the famous fireworks display - showed officers patrolling the crowds with longarm weapons.

In the lead up to the event, Premier Chris Minns had warned that some people may find the sight confronting, with police carrying firearms and weapons that you haven't seen before. But I don't make any apology for that. We want people to be safe in our community, he added.

British tourists Joe and Lucy, in Melbourne during the attack, expressed reassurance from the heavy police presence, as travelers were initially concerned about safety during the New Year's Eve celebrations.

Separately, Minns had urged Sydneysiders to not let the horrible criminal terrorist event at Bondi change their lifestyle, calling instead for defiance and the celebration of the new year. This sentiment resonated with many in the crowd.

As the countdown neared, hundreds of thousands flocked to the harbour, with popular viewing spots quickly reaching capacity. The iconic fireworks served as the starting point for celebrations globally, beginning a chain reaction of New Year festivities in cities like Dubai, London, and New York.