Masked anti-globalisation protestors clashed with police and pulled down barricades on Saturday as a summit of the world's most powerful economic leaders opened in Melbourne.
Police used batons to repel demonstrators from the barriers as up to 1,000 protestors marched through the center of Australia's second largest city where Group of 20 (G20) finance ministers and central bank chiefs were meeting.
Demonstrators hurled a smoke canister at mounted police near the summit venue at the heavily fortified Grand Hyatt hotel and attempted to scale the barricades before being pushed back by a line of baton-wielding foot officers.
The march began peacefully but escalated when a group of demonstrators wearing white boiler suits and face masks briefly seized a motorcycle policeman's bike.
Mounted police then moved in to help their colleague and demonstrators made a rush for the main police barricades near the venue which is surrounded by strict security cordon.
Protestors also attacked a television news crew, according to a reporter, and reports said some were threatening to break into the conference venue to arrest World Bank president Paul Wolfowitz for "crimes against humanity."
As they marched on the barricades, demonstrators chanted "This street's our street" and "One two three four, we don't want your racist war" -- a reference to the Iraq conflict.
Police have blocked off streets around Melbourne's central business district fearful of a repeat of violent protests that shook the city when it hosted the World Economic Forum meetings in 2000.