The deadly explosion that claimed the lives of six Canadians and an Afghan interpreter on Wednesday was the biggest roadside bomb ever seen by the investigators who rushed to the blast site.

The engineers who arrived soon after the explosion occurred described a massive crater, three metres wide by one-and-a-half metres deep.

Lt.-Col. Rob Walker, the head of the Canadian battle group in Kandahar, said the bomb was in the same class as one last April that also killed six Canadians, The Canadian Press reports.

"To be quite honest and truthful, when I looked at it I went 'wow, this is powerful'," Walker said Friday at a news conference.

"I knew looking at the vehicle these young men died instantly."

The soldiers were riding in an RG-31 Nyala armoured vehicle when the blast occurred. Walker said the vehicle was completely destroyed.

However, he said he has not lost faith in the vehicle, which the military considers to be one of the safest and most reliable in the Canadian fleet.

"There was no vehicle -- the RG is one of the best vehicles in the world -- and there was no vehicle that was going to survive that,'' he said, adding that the Taliban's ability to build and detonate improvised explosive devices seems to be improving continuously.

All six of the killed Canadian soldiers have now been identified. They are:

• Cpl. Jordan Anderson, 3rd Battalion, Princess Patricia's Canadian Light Infantry, based in Edmonton;

• Capt. Jefferson Francis, 1 Royal Canadian Horse Artillery, based in Shilo, Manitoba;

• Capt. Matthew Johnathan Dawe;

• Cpl. Cole Bartsch;

• Pte. Lane Watkins;

• Master Cpl. Colin Bason.

Meanwhile, Canadian soldiers were continuing their work in Afghanistan on Friday.

CTV's Paul Workman, reporting from Kandahar, said there is little time for grieving, and Canadian soldiers remain focused on the task at hand.

"I spoke to an officer this morning who is very closely connected to the company to which these soldiers belonged," Workman told CTV Newsnet on Friday.

"He essentially said they will grieve for a few hours, they will then put their feelings aside and get back to work. He said there's really a great frustration among the troops at not being able to get back against these roadside bombs, but he also told me when asked how the troops are holding up, make no mistake about it they're in for the fight."

Defence Minister Gordon O'Connor offered his condolences to the families of the victims on Friday morning, but said Canada remains steadfastly committed to the mission.

O'Connor said Canada is in Afghanistan at the request of the democratically-elected government and he blasted New Democrat Leader Jack Layton for calling for an end to Canada's commitment.

"Thousands and thousands of people were executed by the Taliban and if NATO pulls out of -- as somebody like Jack Layton recommends -- if NATO pulls out of Afghanistan the Taliban would return and that murderous regime would be back and that wouldn't be very good for women and children in that country," O'Connor told CTV's Canada AM.

Calls for reflection

Senior commanders at CFB Edmonton have called for quiet reflection on the recent deaths, rather than political debate on the mission. Four of the slain men were based in Edmonton.

"I would encourage all of you that at this point in time, that the focus must be on repatriating these valiant soldiers and ensuring their families hear a clarion call of love and support from Canada," said Col. Jon Vance on Thursday.

"The families are well aware that there is debate on this mission. Nonetheless, at this particular point in time, the most sensitive and, I think, mature approach, would be to show them ... love and support. These soldiers died in a mission that they believed in, and saw progress occurring."

Also, Prime Minister Stephen Harper said Thursday that it was not appropriate to have an immediate debate about the mission in light of the recent deaths.

"Parliament has approved... (the mission) until February 2009, but obviously today is not the day to have a political debate on the future of the mission, we have the House of Commons for that," Harper told reporters at a press conference in Halifax.

With the most recent deaths, 66 Canadian military personnel and one diplomat have now been killed in Afghanistan.

Thursday violence

Meanwhile, violence has continued in Afghanistan.

NATO announced Friday that a suicide bomber blew up a room full of policemen eating lunch at a southern Afghan checkpoint on Thursday, killing 10 officers and wounding 11. In another deadly exchange, three NATO soldiers were killed in eastern Afghanistan.

The alliance has not disclosed the nationalities of the NATO casualties or the place where the operation took place. Most of the NATO troops in the east are American.

Earlier, authorities said a roadside bomb in the east had killed a NATO soldier Thursday.

More than 3,000 people -- mostly militants -- have now been killed in insurgency-related violence in Afghanistan this year, according to an Associated Press tally.

With files from The Associated Press