More than 500 people have been arrested amid mass demonstrations in Canada's largest city during the weekend summit of the world's 20 largest economies, police said Sunday.
Sporadic violence marred otherwise peaceful protests on Saturday, the first day of the Group of 20 (G20) summit, forcing Toronto police to use tear gas for the first time in the city's history, DPA reported.
The violence continued through the night, prompting authorities on Sunday to crack down on key locations where demonstrators were gathering.
Police arrested dozens of students at the University of Toronto and cleared away a group of about 200 peaceful demonstrators at a make-shift prison created specially for the summit.
Hundreds of protesters roamed Toronto on bicycles on Sunday after more than 10,000 took to the streets a day earlier, confronted by about 12,000 Canadian security forces.
Government officials condemned the violence and defended the nearly 1-billion-dollar price tag for the summit, as police were tasked with protecting about 10,000 delegates and 4,000 journalists.
The outbreak of violence, including smashed shop windows and burning cars, was minimal compared to many previous global summits. Yet it shocked the sensibilities of a city that has had little experience of holding such a major political event.
"I think it was shocking to every citizen," said Toronto Police Chief William Blair. "We have never seen that level of wanton criminality and random violence on our streets."