Regardless of how they feel about the mission, all Canadians grieve for the soldiers killed Sunday in Afghanistan, says NDP Leader Jack Layton.

"All of us are deeply saddened by what we've learned. It's truly shocking," he told CTV Newsnet on Sunday.

In a statement released by the Liberal Party, Leader Stephane Dion said: "I would like to express my sincere sorrow at the news of the deaths of six brave Canadian soldiers in a roadside bombing near Kandahar.  We send our deepest sympathies to their family, friends and comrades as they cope with this terrible tragedy."

Six Canadian soldiers died somewhere west of Kandahar when it is believed a roadside bomb detonated near their vehicle -- the worst single loss of life since troops started serving in the South Asian country in 2002.

Two other soldiers suffered injuries. One had minor injuries, but one might require treatment for his abdominal injuries at a U.S. military hospital in Landstuhl, Germany.

Prime Minister Stephen Harper first announced the news at celebrations in France marking the 90th anniversary of the First World War's Battle of Vimy Ridge.

Layton's NDP have been critical of the Canadian mission in Afghanistan and called for the withdrawal of the nation's 2,500 troops from Kandahar province.

"Well, we don't believe that it's a mission that ultimately can succeed militarily, and I think there's more and more evidence of that," he said, adding today wasn't the day for that discussion.

"I think all of us are very much focused on the comrades, on the families of the fallen soldiers," he said.

"These are very, very brave individuals who do whatever our country asks them to do, and that's the reason that Canadians are so supportive of all of those who are on the front lines."

Dion said in his statement: "We owe a tremendous debt of gratitude to the men and women of the Canadian Forces, who risk their lives to create a safer and more secure world for Canadians and people the world over.

"We remain steadfast in our support for the Canadian Forces personnel stationed in Afghanistan as they work toward the noble goal of bringing peace and stability to this troubled region."

Securing the country

Helena Guergis, secretary of state for foreign affairs and international trade, recently returned from Afghanistan.

She told CTV's Question Period in an interview broadcast before Sunday's developments that securing the country allows for development to begin and aide to filter into the country.

"Once you see the big picture, it all comes together and you realize that we are making incredible progress and it's not easy," she said.

"It takes a lot and you have to ensure that you have the security first of all, in order for a lot of the peace to continue."

Layton described Canada's activities in Afghanistan as a counter-insurgency war, but the debate about that would have to wait.

British military expert Rory Stewart, who lives in the Afghanistan capital of Kabul, told Question Period he thought NATO should change its strategy.

"NATO has a very important roll in stabilizing Afghanistan, but I believe chasing the Taliban around the rural areas, which is what we are doing a great deal of at the moment, is probably a mistake," he said from Washington.

"We are creating unnecessary enemies and we are confronting people who are not necessarily a threat to us."

Omar Samad, the Afghan ambassador to Canada, offered his government's condolences for the deaths. He said the deaths are especially "sad and tragic'' coming on the eve of the 90th anniversary of the Battle of Vimy Ridge.

However, he said NATO's involvement in his country "is still the right mission and the right cause.'' Samd is "sure that people will continue to support it for the right reasons.''

Denis Coderre, the Liberal party's defence critic, said, "Of course there is a reason for us to be in Afghanistan, but we need to send a clear message that there will be a time when we have to pull out, and that time is February 2009."

In May 2006, Parliament narrowly voted to extend the Afghan mission's mandate to that date.

With files from The Canadian Press