MONTREAL -- Former Israeli prime minister Benjamin Netanyahu was forced to cancel a speech at a Montreal university yesterday after a tumultuous protest by pro-Palestinian demonstrators degenerated into violent flare-ups with police and isolated clashes with Jews.

Riot police used pepper spray to disperse hundreds of demonstrators who converged on the downtown campus of Concordia University in a bid to stop Mr. Netanyahu.

The campus in the heart of Montreal has been an uneasy flash point between pro-Palestinian and pro-Israel students for years, and the tensions roiling the university student body erupted again.

Even the presence of 100 city police officers couldn't ensure security at the site and Mr. Netanyahu never made it onto the campus. Later, he took Canadian security forces to task for failing to ensure his ability to speak.

"I think that the people in the government of Canada should not allow these kinds of interferences with the basic rights that Canadians hold dear," Mr. Netanyahu said at a news conference.

"I think it's important to take all the measures in advance, and during such events, to facilitate free speech. I think that is something well within our means.

"In Israel, we enable free debate and free discussion in conditions of much greater duress."

The protest unfurled around the boxy Henry F. Hall Building, a downtown landmark.
Pro-Palestinian demonstrators, some of them holding Palestinian flags and wearing keffiyeh, locked arms to block an entrance to the university, roughing up some people trying to attend the speech.

Montreal Rabbi Howard Joseph and his wife, Norma, a Concordia religion professor, were kicked and punched.

"The women aimed their punches at my breasts," Prof. Joseph said.

Gabriel Riff, who was trying to enter the building, said his kipa (head covering) was pulled off his head. "They threw it to the ground and kicked it away. When I tried to get it they kicked me," he said.

Mr. Netanyahu, who remained in a room at the Ritz-Carlton Hotel while the clashes raged at the campus a few blocks away, said he wanted to deliver his speech but was told it wasn't safe. The university and RCMP decided to cancel the event.

Meanwhile, hundreds of protesters managed to penetrate the building through a side entrance and occupied the front vestibule -- only a few metres from the auditorium where 500 mostly Jewish spectators had gathered to hear the speech.

Demonstrators outside smashed a large plate-glass window in the vestibule and began hurling objects at police inside, prompting officers to fire back with pepper spray.

The acrid gas began to fill the vestibule. As chaos began to take hold, police pushed back the protesters inside. In response, several hurled wooden furniture and metal chairs at the officers from an upper mezzanine.

By lunchtime, the vestibule of Concordia's main downtown building was littered with paper, upturned chairs, broken furniture and the choking aftereffects of pepper spray.

Eight windows were smashed and five people were arrested. Charges included assaulting a police officer, gathering illegally and resisting arrest.

Meanwhile, students on upper floors, who showed up for class as usual, found themselves rushing toward stairwells to escape the searing pepper spray. Several reported tear gas as well, although police deny using it.

"It was panicky," said Sarah Fletcher, a third-year English major. "There were tons of people running up and down the staircase trying to get out."

The RCMP, who were part of a major security operation deployed for Mr. Netanyahu's visit, said they viewed the presence of the student protesters inside the building as a security breach, and couldn't ensure Mr. Netanyahu's safety, according to an organizer of the event.

Concordia is an ethnically diverse university with a large and vocal Arab student leadership, which has clashed in the past with both the university administration and Jewish students.

Administrators tried to persuade Hillel, organizers of Mr. Netanyahu's visit, to move it to another site, according to Don Boisvert, the dean of students. But organizers, saying they have felt under siege by pro-Palestinian students, insisted on holding it at the downtown campus.

"The Concordia campus is a symbol of where Jewish students are under pressure for their views on Israel," said Hillel member David Sachs, 23. "We've been under the gun by Palestinian students and their propaganda thrown in our face. We feel it's important to stick together."

Arab students saw the speech as a provocation. Several complained that the speech was not open to everyone and Arab students were unable to get tickets to attend.

"The man is a war criminal. We don't want our city and our universities to be the harbour of such a war criminal," said Wassim Moukahhal, president of the Arab Students Association at nearby McGill University.

University rector Frederick Lowy said the university weighed the principle of freedom of speech against the security concerns, and decided to go along with Mr. Netanyahu's speech.