Protesters said police were heavy-handed, using tactics that instigated violence rather than quelled it.

They also criticised the media for focusing coverage on violent clashes rather than the broader peaceful marches.

After a day when police admitted losing control of a violent and fast-moving crowd, the arrests came fast on Sunday.

Among those detained, for charges ranging from mischief to assaulting police, were four people who climbed through the city's sewer system and emerged near the locked-down area where world leaders were attending the summit.

About 70 people were also detained after police raided the University of Toronto's downtown campus. Police said they seized weapons, including bricks, rocks and sticks.

Anti-G20 groups started demonstrating in Toronto before the summit, which followed a smaller meeting of Group of Eight industrial nations in a resort town north of Toronto.

The security bill for the events is set to hit around $1bn.