KANDAHAR, Afghanistan (AFP) -- A Canadian soldier has died in southern Afghanistan after being wounded in a suicide blast that also injured three other soldiers, the NATO-led force said Wednesday.

The Canadian defense force announced meanwhile that its troops had opened fire on two civilians, one of whom later died, after they broke through a security cordon around the site of Tuesday's suicide blast in Kandahar city.

The three wounded soldiers were in stable condition, NATO's International Security Assistance Force (ISAF) said in a statement.

Fifteen Canadian soldiers have now died in hostile action in Afghanistan this year. Another three have died in enemy attacks since Canadian forces deployed here in 2001, months after the Taliban were toppled from power.

There are about 2,300 Canadian troops in Kandahar, the birthplace of the extremist Taliban movement ousted in late 2001. It has been waging a determined insurgency focused on the south and east.

The Canadian defense force said in a statement posted on its website that the suicide bombing destroyed two Canadian vehicles in the convoy.

About two hours later a motorcycle traveling at high speed and carrying two people broke through an outer police security cordon at the blast site, the statement said. "The driver failed to heed multiple warnings to stop as he headed towards the inner Canadian Forces cordon. A Canadian ISAF personnel on scene opened fire on the two in a defensive application of our rules of engagement."

The civilians were flown to a Canadian-led medical facility at the main ISAF military base in Kandahar for treatment. One died and the other is in serious condition.

The incident would be investigated, the statement said.

Kandahar city has been hit by several suicide blasts this year, most of them aimed at security forces but killing more civilians.

Kandahar province is among six southern provinces that came under ISAF command in July 31, when the force took over from the U.S.-led coalition that helped to remove the Taliban.

ISAF has 21,000 troops from 37 countries. About 10,000 of its soldiers are in the south, more than double the number of foreign troops in the area last year. The shortage of soldiers was blamed for the resurgence of the Taliban.