TORONTO – Civil liberties groups called for an investigation of police conduct Tuesday after the arrests of 900 people during the massive and sometimes violent protests at the global economic summits over the weekend.

The Canadian Civil Liberties Association called for a public inquiry into security operations at the G-20 and G-8 summits, which resulted in the largest mass arrests in Canadian history and included the use of tear gas and rubber bullets on protesters.

“We have police brutality, illegal searches, arbitrary detentions, people being harassed,” Nathalie Des Rosiers, general counsel for the Canadian Civil Liberties Association, said Tuesday. “It’s unconstitutional, it’s illegal and it should not happen.”

The group, which had 50 human rights monitors at the protests to observe police behavior, also called for an apology to those claiming their civil liberties were trampled. It said in a statement that police conduct was “at times, disproportionate, arbitrary and excessive.”

Toronto Police Chief Bill Blair said Tuesday that less than half of the 900 arrested will be charged, and that many have been released. He said a police task force has been set up to review law enforcement actions during the summit.

Blair praised police for showing restraint, and said no protesters suffered serious injuries.

More than 19,000 security officers were deployed in the G-8 host city, Huntsville, Ontario, and the G-20 host city, Toronto.

A protest of 10,000 organized mainly by labor groups turned violent Saturday, caused mainly by a few hundred people who police described as anarchists. They went on a rampage, smashing storefront windows with baseball bats, torching four police cruisers and prompting police to fire tear gas for the first time ever in the Toronto police force’s history.

Police slapped plastic zip-tie handcuffs on protesters — many of whom say they were rallying peacefully — and escorted them to a makeshift detention center across town.

Along with the arrests, police are also being called into question over an incident Sunday night when they held more than 200 people on a busy downtown intersection for hours in torrential rain.

Detainees included G-20 summit accredited journalists and people who say they were shopping or waiting for public transport.