A roadside bomb explosion ripped through the armoured vehicle of six Canadian soldiers Wednesday, killing them as they returned to their base after a heavy day of fighting in Afghanistan's Panjwaii district.

An Afghan interpreter riding with the soldiers also died in the blast.

Brig.-Gen. Tim Grant, commander of Task Force Afghanistan, said the group was travelling in an RG-31 Nyala armoured vehicle on a gravel road, used often by Canadian convoys and considered to be safe.

Two of the slain soldiers have not been identified at the request of the families, but the military has named the other four:

• Capt. Matthew Johnathan Dawe
• Cpl. Cole Bartsch
• Pte. Lane Watkins
• Master Cpl. Colin Bason

Dawe, Bartsch and Watkins were all members of 3rd Battalion Princess Patricia's Canadian Light Infantry, based in Edmonton.

Bason was a member of the Royal Westminster Regiment, based out of New Westminster, B.C. His mother, Ann Bason, said her son was probably one of the first reservists to join the mission, when the call went out for soldiers to go to Afghanistan.

"He was very proud that he got picked. The sad thing is he only had six weeks to go before he was on his way home," she told CTV British Columbia. "But how many people get to do the things they really love? And he really loved the infantry."

She added: "My sympathy goes out to all the other mothers, fathers, husbands, wives and children of the other ones that have passed away, while they were over there. I hope God will be with them, and hope the other ones come home safely."

Grant called the slain soldiers "exceptional young men," but said their deaths "will not diminish our resolve and our determination to bring to Afghanistan a peaceful land for the children of this country."

The attack happened about 20 kilometres southwest of Kandahar while the soldiers returned to their forward operating base west of Kandahar city, after conducting a joint operation with the Afghan National Army.

Grant told reporters the RG-31 is considered one of the safest vehicles in the Canadian fleet, and was driving on a road that the military has used regularly over the past month.

When asked what steps the military is taking to reduce deaths caused by IEDs, Grant said troops are finding and disarming IEDs more often than not.

"When IEDs are successful they get reported. What doesn't get reported is ... the many number of times where we neutralize IEDs -- when they're pointed out to us by locals, or we find them ourselves. We dismantle them and we exploit them, so we can learn how to defeat them," Grant told reporters.

"We're not perfect, and we do miss some, as we've seen today. But the battle against the Taliban and the battle against their choice of weapons . . . is successful."

CTV's Paul Workman, reporting from Kandahar, said the deadly attack is sure to heighten tension among Canadian troops.

"For many of these soldiers the rotation is almost over. They're thinking about getting on those airplanes and going home to see their families and no one wants to be a late casualty, and that's what we've seen today," Workman told CTV Newsnet.

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

Earlier violence

Earlier Wednesday, AP reported that three separate clashes left 20 militants and one police officer dead in Afghanistan.

The gun battles were sparked after militants attacked several checkpoints in Ghazni province in Afghanistan's south, the province's police chief told The Associated Press.

The fighting left 13 militants and one police officer dead.

In separate gun battles in Zabul province on Tuesday, U.S.-led coalition forces fought with suspected Taliban militants in the province's Shahjoy district.

Seven militants were killed and six others were wounded in those battles, according to a spokesperson for the province's governor.

More than 2,400 people have been killed so far this year in Afghanistan, including civilians, militants and troops according to an AP tally.

With files from The Associated Press