Amnesty International Canada is calling for an independent review of the security measures put in place for the G8 and G20 summits.

Human rights suffered considerably during protests in Toronto, the group said.

The police did have a difficult job to do, said Alex Neve, Amnesty International Canada's secretary general, but he questioned the extent of the security buildup.

"We're concerned that both the extensive lead-up to the summit — the heavy, heavy police presence — [and] all of the talk of new weapons and unclear laws really led to quite a considerable chill."

Amnesty said the heavy police presence in Toronto, as well as acts of vandalism and violence by some protesters, created an atmosphere of fear that kept many from taking part in peaceful demonstrations.

Meanwhile, police defended their actions throughout the G20 summit, which saw more than 900 people arrested over the weekend.

Changed tactics

Police acknowledged they changed tactics after Saturday's chaos, in which windows were smashed and some police cruisers set on fire, but they insist their methods were lawful.

"Everything that our officers did in the Toronto Police Service was for the safety of the law-abiding citizens in this city, and we did the best we could," said Staff Supt. Jeff McGuire. "I'm not suggesting we're perfect."

McGuire said the city faced "very trying circumstances" that neither citizens nor many police officers had faced.

"[Police] didn't do things maliciously, they did them with the intent of providing public safety for the citizens of Toronto."

McGuire added that in some large gatherings Sunday, people were initially detained but later released at the scene without charge.

'Very, very difficult job'

Toronto Mayor David Miller commended police for the overall job they did, even as questions were raised about their tactics.

While some critics said the police were too lax on Saturday when the worst of the violence flared up, others have called Sunday's widespread arrests heavy-handed.

"I think those criticisms — I heard both of them from the media and from others — illustrate the very, very difficult job the police had in trying to allow … people’s right to free speech and demonstrate, and at the same time effectively deal with people hiding in demonstration who came to Toronto simply to commit crimes," Miller said.

"That is almost impossible balance for the police to do. I think in the very, very big picture — compared to similar events in other cities I think people need to be supportive of the way it was handled," he said.

In the wake of the G20 summit, at least one group has formed on Facebook calling for a public inquiry into the volatile events of the weekend.