Bell tolls for peace atop Harbour Bridge

Bells have chimed atop Sydney's Harbour Bridge, calling for peace throughout the world.

Olympic gold medallist Sally Pearson led World Peace Day festivities on Sunday by ringing a bell at midday and taking a minute's silence alongside representatives from the United Nations.

"Creating world peace is a central ideal for all Olympians," the hurdle champion said.

The Sydney bells kicked off events across the globe, including the ringing of the peace bell at UN headquarters in New York.

The event called for 24 hours of worldwide ceasefire and non-violence in all combat zones to allow civilians to be evacuated and access for humanitarian aid.