Montreal — A scheduled speech by Benjamin Netanyahu at Concordia University was cancelled Monday as police used pepper spray in a clash with demonstrators who wanted to thwart the former Israeli prime minister's visit to Montreal.

Security officials at the university said the event was called off because about 200 protesters crowded inside the downtown university building where Mr. Netanyahu had been scheduled to speak.

Protesters inside the building tossed chairs and newspaper boxes at police before being driven back by police batons and pepper spray.

Police arrested at least five people following a melee inside the F. Hall building as other demonstrators tried to get in by smashing a window.

The facility was evacuated and the speech cancelled a few minutes later. A number of people were seen hunched over on a nearby sidewalk, coughing and gagging on the pepper spray.

Mr. Netanyahu was never in the building and his handlers had said he would not give his speech unless his safety could be guaranteed.

Some of the several hundred people who gathered at the downtown campus on Monday to protest Mr. Netanyahu's visit accused him of being a war criminal and said he has no right to a pulpit from which to voice what they call his anti-Palestinian views.

"There's no free speech for hate speech," said protester David Battistuzzi, 24, a Palestinian activist and former Concordia student.

"This man said in 1989 Israel 'should have taken advantage of the Tiananmen Square massacre to expel the Palestinians from Israel.'

"He's a violent man... this man is a war criminal."

Following the cancelled speech, a visibly tense Mr. Netanyahu blasted the protesters, accusing them of supporting terrorism and opposing democracy.

"These were, unfortunately, misguided supporters of the worst kind of militancy and the worst kind of zealotry that you see in the world today," Mr. Netanyahu told reporters at a downtown hotel.

"They're supporting Saddam Hussein, they're supporting [Yasser] Arafat, they're supporting [Osama] bin Laden."

Mr. Netanyahu also said officials could have done a better job to ensure his speech was not disrupted. He suggested the most violent protesters could have been arrested prior to the event.

Mr. Netanyahu said he would likely discuss Monday's incident on Tuesday during a scheduled meeting with Prime Minister Jean Chrétien.

Mr. Netanyahu, who was Israel's Likud Party prime minister from 1996 to 1999, is scheduled to speak Tuesday in Toronto, where more protests have been planned.

Tensions at Concordia remained high throughout the afternoon as shouting matches broke out between Jewish and Arab students.

Police cleared the area in front of the Hall building by late afternoon.

The demonstration was not the first time Jewish and Palestinian supporters have clashed at Concordia. The school's student union courted controversy last year for its pro-Palestinian stance and anti-establishment politics.

Last spring, various student groups helped organize two large pro-Palestinian rallies calling for the end of the Israeli occupations in towns in the West Bank.

Last fall, a Jewish advocacy group said a student handbook distributed at Concordia might have been anti-Semitic and a blueprint for terrorist groups.

Last year's version of the annual handbook, entitled Uprising, opened with a poem about the intefadeh, the Palestinian uprising in Israeli-occupied territories. It also said the North American media was largely controlled by Zionists.

Earlier Monday, Mr. Netanyahu told a news conference that the world would be making a mistake if it failed to support the U.S.-led effort to oust Iraqi President Saddam Hussein.

Mr. Hussein has already proven he is prepared to wage war and he must be stopped before he acquires nuclear weapons, Mr. Netanyahu said.

"I think the entire world, and certainly the entire democratic world, should be worried about a regime that knows no bounds on the use of force," he said.

"To wait until this tyrant develops nuclear weapons would be a big mistake."