Thousands took to Montreal streets Tuesday evening in the latest march against austerity, in a march that police declared illegal from the outset, as the group had declined to offer their itinerary, required under bylaw P-6.

When it was over police had arrested four people for assault, two people were taken to hospital for minor injuries, and half a dozen police cars were vandalized.

The event was organized by the Revolutionary Student Movement, which describes itself as "an association of young Communists and revolutionary anti-capitalists."

The group met at 9 p.m. at Emlie Gamelin Park outside the Berri metro and shouted "the street is ours," as a police helicopter flew overhead.

Police had formed a wide perimeter around the park and the demonstrators booed and jeered their presence, chanting the phrase "we stole nothing," the same phrase the police used in their demonstration against pension cuts.

The tenor of the event intensified as pyrotechnical devices were tossed at police at about 9:45 p.m. Protesters were seen wielding makeshift devices such as traffic cones. Many demonstrators were sporting masks, in defiance of the P-6 bylaw ban.

The demonstrators clashed with police after riot squad officers attempted to corral a small group of protesters. At least one car windshield was smashed, according to police, who employed smoke in an attempt to quell the crowd.

Police reported two arrests as of 10:30 p.m. About a half dozen police cars had their windshields smashed and a building was spray-painted at Bleury and Ste. Catherine.

At 10:45 p.m. police ordered the demonstrators to disperse.

The protest followed a smaller demonstration earlier in the afternoon which saw three people arrested.

The leader of the Quebec Women's Federation offered her support to the group, "Dear students. You are not alone. Continue to fight paternalism, state violence, sexism and austerity," Alex Conradi wrote on her Twitter account.

Education Minister Francois Blais stated earlier Tuesday that the semester would not be extended, as it was in 2012, so no accommodations would be made for those boycotting classes or striking.

A similar march took place in Quebec City Tuesday evening, which led to what police describe as "two mass arrests."

Small crowd so far gathering for anti-austerity protest in downtown #Montreal #manifencours pic.twitter.com/4zPer1nIpc — Vanessa Lee (@VanessaLeeCTV) March 25, 2015

Student protesters flood the street at Berri and Ste-Catherine http://t.co/nI7IsXiyNE — Kevin Gallagher (@KGallagherCTV) March 25, 2015

Riot police move in at St-Laurent and Rene-Levesque, separate group. http://t.co/BkYtpjqKBs — Kevin Gallagher (@KGallagherCTV) March 25, 2015