Like its parent company Exxon Mobil, Imperial, Canada's biggest gasoline retailer, is a vocal opponent of the international agreement on cutting greenhouse gas emissions, an accord Canada has agonized for several months over ratifying.

The protests marked the start of Greenpeace actions planned in numerous countries this week to urge motorists to boycott Esso fuel, the group said.

"Greenpeace is targeting Esso because Esso is doing the most of all the oil companies to stop international action on climate change," said Jennifer Story, head of Greenpeace Canada's "Stop Esso" campaign.

The protests followed a demonstration last month before a Group of Eight environment ministers meeting, in which Greenpeace activists put solar panels atop the Calgary home of Alberta Premier Ralph Klein, known for his anti-Kyoto stance.

Montreal police said they arrested five activists for disturbing the peace after firefighters cut the chains that fixed them to pumps at a downtown Esso station.

Two protesters in Toronto, who fixed themselves to pumps with heavy bicycle locks, were released shortly after being hauled in, Greenpeace said. At least some of a dozen activists at the site wore U.S. President George W. Bush masks.

In Vancouver, police arrested one of 12 demonstrators, the group said. The woman was expected to be released yesterday.

"We appreciate their right to express their views," said Richard O'Farrell, spokesman for Toronto-based Imperial. "However, we say the actions they're taking at service station sites and chaining themselves to gasoline pumps is a safety concern for us and an environmental concern. We don't believe it's the right way to demonstrate a point of view."

Imperial has long opposed the Kyoto protocol, which would commit Canada to cutting emissions of greenhouse gases like carbon dioxide to 6 percent below 1990 levels by 2010-2012. The gases are blamed for global warming.

The firm's recently retired chairman, Bob Peterson, said the deal would wreak economic havoc in Canada, a net energy exporter, without curing any environmental ills.

Last year, Bush pulled the United States out of the accord, saying it would harm the economy. Numerous Canadian industrial interests have said their country's participation is pointless without the United States, the biggest emitter.

O'Farrell said Imperial believed global warming may "potentially have an impact on society" and was working to cut its emissions and improve its energy efficiency.

"We just don't happen to believe in the Kyoto protocol as the right solution," he said.

Ottawa has backed off a previous goal of ratifying Kyoto this year, saying it needs more consultations. Prime Minister Jean Chretien reiterated last week that Canada should be credited for its clean energy exports to the United States, a position the European Union opposes.

"What we hope to accomplish is to draw the public's attention to what we think is one of the root causes of stalling on the Kyoto protocol, and give Canadians an outlet," Story said.

"If they are concerned about the need for climate change action, then they should not buy Esso gas."