At least 130 people have been arrested in the Canadian city of Toronto, in a violent show of opposition to the G20 summit.
Masked protesters rioted across Toronto, setting police cars ablaze and smashing shop windows in a violent show of opposition to the anti-G20 summit.
Police used teargas at times to control the crowd of several thousand.
Police say the protest began when several hundred anarchists broke away from a larger, peaceful protest group.
The G20 meeting of the world's richest and emerging nations followed the G8 summit of the wealthiest countries.
Toronto police chief Bill Blair admitted police had struggled to control the crowds, who at times numbered several thousand.
During an afternoon and night of rioting, police cars were set ablaze in at least two areas, including the city's Bay Street financial core, while protesters on Queen Street smashed storefronts and damaged media trucks.
By evening, some protesters had advanced to the metal fence which is sealing off the area where heads of state from the Group of 20 industrialized and developing countries began meeting on Saturday.
Banks, coffee shops and small stores were also targets and protesters looted at least one retailer, storming out with both clothing and the white arms and legs of fashion mannequins.
"A relatively small group of people ... came clearly with the intent of damaging property and perpetrating violence," Toronto Mayor David Miller told a news conference. "They're criminals that came to Toronto deliberately to break the law."
The initially peaceful march numbered in the thousands when it began in the early afternoon, organized by labor groups that say G20 economic policies favor the rich.