OTTAWA (Reuters) - A majority of Canadians support the country's expanded military mission to Afghanistan, even though they realize there is a risk of casualties, according to a poll released on Wednesday.

The Ekos poll, provided to Reuters, showed that 70 percent of those surveyed said they backed the mission while 28 percent were against it.

The result contrasts with a survey last week that said 62 percent of Canadians were against sending troops to Afghanistan.

Canada contributed 2,000 troops to a NATO-run force in Kabul after the September 11 attacks. By next month it will have 2,300 troops in the volatile southern city of Kandahar as part of another NATO mission.

Canadian troops in Kandahar are already coming under frequent attack. Eight Canadian soldiers and a diplomat have been killed in Afghanistan since 2001.

"People distinguish between the Canadian mission in Afghanistan and the war in Iraq. They see it as part of Canada's traditional role in helping sustain peace around the world," said Paul Adams of Ekos.

"People understand it's a robust role and they're comfortable with it. But we're not suggesting it (support for the mission) is so strong it can't be moved," he told Reuters. Adams said the picture could change if Canadian troops started taking significant casualties.

Last week's survey, by the Strategic Counsel, prompted defense officials to say they needed to do a better job of explaining why Canadian troops were in Afghanistan.

Ekos polled 1,002 people between February 6 and February 14 and the results are considered to be accurate to within 3.1 percentage points, 19 times out of 20.