Master Cpl. Scott Francis Vernelli, Cpl. Tyler Crooks, Trooper Jack Bouthillier and Trooper Corey Joseph Hayes were killed Friday in two roadside bomb blasts in Kandahar province. Eight Canadian soldiers were also wounded. (Department of National Defence)Four Canadian soldiers were killed and eight others wounded in two separate roadside bomb blasts outside Kandahar city on Friday, military officials said.

Master Cpl. Scott Vernelli and Cpl. Tyler Crooks — both of November Company, 3rd Battalion, Royal Canadian Regiment — died when an improvised explosive device exploded near their patrol in the Zhari district, about 40 kilometres west of Kandahar. The incident happened about 6:45 a.m. local time, Brig.-Gen. Jonathan Vance said during a news conference in Kandahar.

One Afghan interpreter was killed and another injured in the attack.

Trooper Jack Bouthillier and Trooper Corey Joseph Hayes, both of the Royal Canadian Dragoons, were killed when their vehicle struck a roadside bomb around 8:45 a.m. local time in the Shah Wali Kot district. That region is about 20 km northwest of the city and has seen an increase in Taliban activity.

All the soldiers who died were based in Canadian Forces Base Petawawa.

All of the injured soldiers are in stable condition in Kandahar and were able to call their families, said Vance, the commander of Canadian troops in Afghanistan.

Largest joint U.S-Canadian offensive since Korean war

The CBC's Alan Waterman, reporting from Kandahar, said the military have not released information about the identity or condition of the injured yet. Commenting after Vance spoke, Waterman said at least one of the eight had been flown to Germany.

Waterman said the soldiers were nearing the tail end of a four-day offensive that was the largest joint U.S.-Canadian offensive since the Korean war.

The offensive, which began Tuesday, saw Canadian and U.S. soldiers split into two battle groups. They went into a large swath of land in Kandahar's Zhari district to engage Taliban forces, who usually try to organize munitions and prepare plans for the fighting season in the summer, Waterman said.

The operation was aimed at disrupting the Taliban as they organized and to "push back the fighting season as much as possible."

"So, an extremely large operation but of course in the midst of this we've lost four of our own here, [and] eight more injured in this four-day operation."

'Success in war is costly'

"Please do not think of these incidents as a failure on the part of any person or the mission itself," Vance said.

Master Cpl. Scott Vernelli (right) and another soldier set up a defensive position during an assault on a Taliban command centre in Zhari District, Afghanistan, on Friday. (Murray Brewster/Canadian Press)"These wonderful Canadian men were, at the moment of their deaths, engaged directly in the continuing work to keep the insurgency sufficiently at bay to ensure safety for the population and to preserve our ability to meet the objectives of the Afghans, the international community, and the government of Canada," he said.

"And those objectives are intended to meet the needs of a desperate Afghan population. Success in war is costly."

Vance described Vernelli, 28 and married with a six-month-old daughter, as "an enthusiastic and dedicated father."

"He was a terrific athlete, very funny and, ironically enough, always able to joke at the worst of times," Vance said of the Sault Ste. Marie, Ont., native.

Crooks killed on 24th birthday

Crooks, a native of Port Colborne, Ont., was a keen and motivated soldier who "loved dirt-biking and was a Texas Hold 'em card shark," Vance said. He died on his 24th birthday.

"He's remembered by his friends as the kind of guy who would do anything for you without even being asked."

Vance said Bouthillier, a 20-year-old from Hearst, Ont., was a joker who always had everyone laughing. "His enthusiasm and his unswerving duty for work inspired other soldiers."

Hayes, 22, who grew up in Ripples, N.B., "was a proud and dedicated soldier who always put his friends and family before himself," Vance said.

"His friends remember him not only as a friend and a comrade-in-arms, but a brother who Inspired them to stand up in the face of danger and do what was right."

PM offers condolences

Prime Minister Stephen Harper offered his condolences in a statement to the families of the soldiers who lost their lives.

"Canadians and the Government of Canada stand proudly in support of our Canadian Forces members as they strive to bring safety and stability back to Afghanistan. Master Corporal Vernelli, Trooper Bouthillier, Corporal Crooks and Trooper Hayes' sacrifice will not be forgotten," Harper said in his statement.

"I join with all Canadians in wishing a prompt and full recovery to the other eight soldiers injured in these incidents."

The latest deaths bring the number of Canadian military fatalities in Afghanistan to 116 since Canada's combat mission there began in 2002. One diplomat and two aid workers have also been killed.

There are 2,830 Canadian troops serving at Kandahar Airfield and Camp Nathan Smith, the home of the Provincial Reconstruction Team in Kandahar city.

With files from the Canadian Press