Montreal - Demonstrations against a World Trade Organization meeting degenerated into vandalism of downtown stores and luxury vehicles Monday, with police eventually arresting more than 200 people.

While the majority of the 400 or so activists gathered for the demonstration were peaceful in their opposition to the informal meeting of about 25 international trade ministers, pockets of violent protest early in the day prompted police to declare the entire gathering illegal.

Ten police officers and a news photographer suffered minor injuries in scuffles with people trying to shut down the three-day WTO meeting, said Montreal police spokesman Ian Lafreniere.

But the incidents did nothing to halt activity inside the Sheraton Centre, where the meetings officially get underway Tuesday.

International Trade Minister Pierre Pettigrew spent much of the day Monday meeting with representatives of various non-governmental organizations and business groups concerned about the negotiations intended to broker a new trade treaty.

On the streets, protesters shouted their frustration at being kept well away from the meeting by metal barricades and city and provincial police officers dressed in riot gear.

A short time later, some protesters tossed objects through the windows at Gap and Burger King outlets on busy Ste-Catherine Street. A Canadian Forces recruitment centre was also vandalized.

At several points in the demonstration a few protesters threw large garbage dumpsters and barricades from downtown construction sites into the street in an effort to block the police who followed several metres behind in their vehicles.

Many businesses, including the CIBC branch near the Sheraton Centre, took preventive measures by boarding up their windows. Others closed for the day.

The smell of vinegar permeated the air at certain points as demonstrators doused their bandanas in anticipation of a shower of tear gas or pepper spray from the riot police. Some wore gas masks. No gas or pepper spray was used.

Most of the arrests were made a few hours after the protest broke up as the activists gathered at a pre-determined meeting point several blocks east of downtown.

Those rounded up will face charges of mischief, obstructing justice and taking part in an illegal protest, Mr. Lafreniere said.

"It was established as an illegal protest, a riot," Mr. Lafreniere said. "So because of that we gave warnings to the people who were taking part in that protest. People were still gathering together. That's the reason why we followed them to this location and that's the reason why we made the arrests."

However, protesters said they were holding a meeting to discuss a number of issues including globalization and human rights. They said they weren't part of the earlier violence.

"We find it disappointing and incomprehensible that police arrested people in the green zone," said Melanie Sylvestre of the Popular Mobilization Against the WTO.

Ms. Sylvestre said the so-called green zone, just east of the downtown core, is an area where protesters can meet, relax and plan their strategy.

She said even though the number of protesters wasn't overwhelming, more demonstrations were planned for Tuesday.

Mr. Lafreniere confirmed anti-globalization activist Jaggi Singh, who has been arrested at several other international trade meetings, was detained for violating his probation conditions.

Protest organizer Stefan Christoff defended the violence against the downtown stores, saying the Gap is a multinational corporation that runs sweatshops.

"These are very legitimate targets, as the WTO is a legitimate target," said Mr. Christoff, who denounced the police presence as a militarization of the city.

Several luxury vehicles, including a BMW sport utility vehicle parked downtown, were defaced with graffiti. Scrawled on the pavement in front of the BMW was the message, Get Some Real Priorities. A parked Porsche also had its front window smashed.

At least one protester denounced the vandalism at the stores as unnecessary.

"Should there be a protest in front of the Gap?" asked Montreal lawyer Marc Stamos. "Absolutely. Should they damage the store? I don't think so. I think that goes too far.

"You can't protest against violence and poor treatment against one person and then go do it yourself. That's hypocritical to me," added Mr. Stamos, who is giving up his fledgling law career to devote more time to social issues.

Protest organizers, who planned further action Tuesday and Wednesday, said they won't be deterred from the fact they were unable to get close to the Sheraton on Monday.

Mr. Pettigrew, who expressed his dismay at the vandalism, said the anti-globalization movement has lost steam in the last few years.

"It has been replaced by a view that globalization can not be stopped, and possibly should not be stopped," Mr. Pettigrew told a news conference Monday.

"But it should be tempered, it should be influenced, it should be managed in a way that better serves all citizens."

Mr. Pettigrew even attempted to inject some humour into his assessment of the protesters' action.

"I was very sorry to see some individuals, masked, with two-by-fours," he said.

"You know I like softwood lumber but I don't like it in the hands of protesters breaking windows. I find it unacceptable. There is no excuse for that."

Mr. Pettigrew is chairing this week's meeting, which will assess just how far apart the WTO's 146-member countries remain as they approach the half-way point in negotiations for a trade treaty known as the Doha Development Agenda.

The meeting will likely be the last chance for the ministers to take stock of the negotiations and determine what kind of flexibility is still needed heading into a crucial full-scale WTO meeting in Mexico in September.

At the heart of a potential deal is agriculture.

Developing countries, which dominate the WTO membership, and other countries such as Canada want the United States and Europe to eliminate about $300- billion (U.S.) in annual agriculture subsidies.

Many of the demonstrators say the most powerful countries within the WTO are not doing enough to help the poorer countries make gains in areas such as agriculture and access to generic drugs.