Four Canadian soldiers were killed in southern Afghanistan on Saturday when their vehicle was hit by a roadside bomb, a Canadian military spokesman said.

Corporal Matthew David James Dinning of the Headquarters and Signals Squadron of 2 Canadian Mechanized Brigade Group, Petawawa, Ontario, was killed when the armoured G-Wagon he was riding in was truck by a roadside bomb near the Gumbad platoon house at about 7:30 a.m. Kandahar time, April 22, 2006. [Reuters]

Violence has surged in Afghanistan since the Taliban announced last month they had launched a spring offensive in their campaign to rid the country of foreign forces and topple the Western-backed government.

"All of the occupants of the vehicle were killed," said the spokesman, Lieutenant Mark MacIntyre.

The four men were traveling in an armored jeep in the volatile Shah Wali Kot district of Kandahar province when the blast hit, he said.

Bombardier Myles Mansell of Victoria, British Columbia, Lieutenant William Turner of Edmonton, Alberta and Corporal Matthew Dinning of Petawawa, Ontario were killed.

Fifteen Canadian soldiers and a diplomat have been killed in Afghanistan since Canada first sent troops after the Taliban were ousted by U.S. and Afghan opposition forces in late 2001.

Canada has about 2,200 soldiers in the Afghan south where it commands a multi-national force based in Kandahar.

Brigadier General David Fraser, the Canadian commander of the force, said his men would not be deterred by the loss.

"While we are saddened by their loss, we will not forget them or their sacrifice," Fraser said in a statement.

"We will redouble our efforts in southern Afghanistan in their memory," he said.

There was no immediate claim of responsibility for the blast but the Taliban have claimed a string of similar attacks in recent months.

Thirteen American troops have been killed in an intensified Taliban insurgency this year.

Nearly 60 Americans were killed last year, the worst for U.S. forces since they invaded in 2001 to oust the Taliban from power.

NATO TROOPS ARRIVING

Despite the rising level of violence, the United States is planning to trim its force of more than 19,000 troops in Afghanistan by several thousand.

At the same time, NATO members including Britain, Canada and the Netherlands, are taking on more responsibilities in the volatile south.

Up to 1,600 Dutch troops will soon move in to Uruzgan province and about 3,300 British troops will soon be arriving in another violence-plagued southern province, Helmand.

Some critics say NATO troops risk getting bogged down in a relentless insurgency that is being funded in part by Afghanistan's huge narcotics trade.

Canadian Prime Minister Stephen Harper, who has faced questions from opposition politicians about Canada's deployment, said this month Canadian troops would be in Afghanistan for years to come.

He refused to accede to an opposition party request to commit to a vote in parliament on any extension of the Canadian deployment beyond early 2007.

In a separate incident on Saturday, two bombs badly damaged the home of an Afghan politician in the generally peaceful north but caused no casualties.

A security official said Taliban insurgents or their allies might have been responsible.

Though mostly active in the east and south, the Taliban have claimed responsibility for attacks in the west and north too.