KANDAHAR AIRFIELD, Afghanistan — Two Canadian combat engineers were killed and five other Canadians were injured on Sunday when their armoured vehicle struck an improvised explosive device while travelling in Dand District southwest of Kandahar City in Afghanistan.

Maj. Yannick Pepin, 36, commander of the Valcartier, Que.-based 51st Field Engineers Squadron of the 5th Combat Engineers Regiment, was the highest ranking Canadian to die in combat in Afghanistan. Cpl. Jean-Francois Drouin, 21, of the same unit also died in the blast.

The five wounded soldiers were listed as being in good condition. One of them was already released Sunday from hospital.

Pepin is survived by his partner, Annie, and their two children, Alexandra and Charles. Drouin leaves behind his partner, Audrey.

"Everybody has fear in a mission," Pepin said at a ramp ceremony early last month for two of his comrades who had died while examining damage to a vehicle struck by an IED. "If you don't, you're not normal. My sappers go first ahead of everyone to save the lives of civilians and soldiers."

Despite the deaths of Sapper Matthieu Allard and Sapper Christian Bobbitt on Aug. 1, Pepin, who joined the army in 1999, said his unit would only take 12 hours to mourn before getting "back on the road."

Pepin and Drouin were attached to the Royal 22nd Regiment battle group and were in the last weeks of their six-month tours in Afghanistan. The French-speaking Van Doos are to be replaced soon by a battle group drawn largely from the Alberta-based Princess Patricia's Canadian Light Infantry.

"We lost two of our best soldiers," Roch Lacroix, deputy commander of Task Force Kandahar, said on Monday. "Yannick possessed human values and remarkable compassion."

Proof of this was the time when Pepin stopped while on patrol to fetch a kite that had been caught in his vehicle's antenna "and handed it to a small Afghan child who thought it had been lost," the colonel said. "On that day we wore a big grin."

Drouin was a great favourite of his comrades, who called him "Big Drou," Lacroix said. He had been an engineer for only three years but had received an "accelerated promotion" to corporal before leaving for Afghanistan with his unit.

"The promotion was testimony of the high regard in which he was held and his devotion and desire were unsurpassed," he said. "He was a very generous man with a heart as big as the three barbells he liked to lift at the gym.

"He was a bon vivant who liked to make others laugh. His favourite phrase was: 'Why do tomorrow what you can do today.' "

Pepin and Drouin were the 128th and 129th Canadian soldiers to die in Afghanistan since the first Canadian troops came to this war-plagued Asian nation early in 2002. Twenty-three of those deaths have occurred this year.

During the first four years of Canada's war in Afghanistan, the Taliban favoured attacks by suicide bombers. During this period only eight of the 44 Canadian deaths were the result of IED blasts striking vehicles. However, since 2007 homemade landmines often fashioned out of old Soviet ordnance or farming chemicals have become the Taliban's weapon of choice.

Over the past 32 months, 58 of Canada's 85 deaths have occurred when vehicles drove over IEDs. Six more Canadians died when they stepped on IEDs during foot patrols. Another three Canadians died while trying to defuse the homemade devices.

A three-man crew from Radio Canada on a brief visit to the country was travelling with the convoy that was struck Sunday at about noon. The reporter, producer and cameraman were not injured in the blast. They declined requests for interviews.

There has been a spike in coalition deaths this summer. A surge in violence had been predicted several months ago by leaders of NATO's International Security Assistance Force after U.S. President Barack Obama that he was dispatching more than 20,000 fresh U.S. troops to Afghanistan. Most of those forces are now in launching operations in Kandahar and neighbouring Helmand province.

There have always been more coalition and insurgent casualties during the summer months as this is traditionally Afghanistan's so-called "fighting season." The season generally begins in April. By November many insurgents have left the south's fertile and heavily populated river valleys, migrating to sanctuaries in mountainous tribal areas of Pakistan before heavy snow closes the mountain passes between the two countries.

Task Force Kandahar includes about 2,500 Canadian soldiers in Afghanistan and about 300 others in the region. About 1,000 U.S. infantry troops are attached to the Canadian task force.