MONTREAL - After a peaceful demonstration during the afternoon of May 22, an evening protest turned violent leading to at least 100 arrests in downtown Montreal.

Repeating the chants of the past 100 days of protests against the Charest government, demonstrators and police exchanged rocks and tear gas as over 1,000 took to the streets in the evening.

After two hours the protest turned violent, and Montreal police said that 20 people were arrested for mischief and armed aggression towards officers.

Group arrests were made at several locations near McGill University, in the downtown core, and throughout the Latin Quarter.

Montreal police also confirmed that one protester was struck by a car during the chaos, however they could not confirm the extent of the injuries. By the end of the night's mayhem four to six people were taken to hospital.

Despite the adoption of emergency legislation last Friday barring gatherings of more than 50 without notice, Montreal police held off from declaring the protest illegal until officers began to be pelted with beer bottles.

One protester said he felt it was obvious that police were having difficulty dealing with crowds night after night.

"I think there could be a lot more communication between the police and protesters. I think it's clear the police are overwhelmed, especially because nightly protests have been going on for weeks on end and these kinds of nightly protests are tiring out police," said Gonzo Nieto.

After violent protests over the weekend, Tuesday's chaos was a return to the violence that many have begun to expect during nights in Montreal.

The spirit of protesters was lifted early in the evening when they received news that the union representing the Montreal transit service's bus drivers had asked its members to stop transporting riot police.

In a written statement executives from the public transit union local SCFP 1983 said they felt Law 78 was unjust, and could interfere with future strike and protest activities.

They were therefore asking bus drivers not to transport police.