A shockingly ugly altercation between riot police and an aggressive contingent of protesters unfolded at a convention of the governing Quebec Liberal party in Victoriaville, Que.
At a news conference Thursday, police said the event began peacefully but deteriorated rapidly after a small group of so-called "professional" rioters joined the student crowd.
Provincial police spokesman Capt. Jean Finet says the way officers handled the riot was measured, considering they were facing the most violent protest they'd encountered in more than a decade.
"This riot was without a doubt the most violent we've seen in the last 10 years, going back to the Summit of the Americas (in Quebec City) in 2001," said Finet.
"The Surete du Quebec had to use the necessary force to push back and restore order. It was obliged to do so."
Police have been accused of lashing out at protesters without warning.
There have been plenty of allegations in recent days that officers overreacted to small groups of stone-tossing protesters — by quickly declaring the demonstration illegal, opting for heavy amounts of chemical irritants, firing rubber bullets and detaining busloads of people.
Several protesters suffered severe injuries, including one young student who lost his eye. Another suffered skull trauma and a woman had a shattered jaw.
But Finet said the force consulted with a pathologist who looked at the medical records of those three people — and he said the opinion was that two were not injured by police rubber bullets. He said the third person might have been injured by a rubber bullet, but an investigation will examine that question.
Police said a small group of hardcore protesters was responsible for the violence, tossing rocks, billiard balls, chunks of pavement and ball bearings at them.
Many protesters and police officers were injured by the debris, Finet said. He added that plenty of warning was given before police reacted.
Finet went over the events of the evening in a methodical, almost minute-by-minute account Thursday. Finet said things turned sour just after 6:30 p.m., when protesters tried to breach the barricade around a conference centre.
Police said it took more than three-and-a-half hours to bring the situation under control. He said the chaos stopped an ambulance from providing aid to one injured person.
Finet denied the accusation that officers fired rubber bullets at protesters' heads. He said five police officers were trained to use the weapons and they fired a total of 33 times.
"At no time did our officers target or fire in the direction of a person's head or other vital parts," Finet said.