Seven passers-by were hurt in the car-bomb blast in the centre of the southern city of Kandahar on Thursday. None of the Canadian troops were injured in the explosion.

The violence came a day after one of the biggest battles in the past year between US-led forces and Taliban insurgents.

A US and a Canadian soldier were killed in the fighting in the southern province of Helmand, along with 32 Taliban insurgents, on Wednesday, military officials said.

The Taliban say they have launched a spring offensive in their campaign to drive out foreign troops and defeat the Western-backed government.

Security forces in Kandahar arrested nine suspected Taliban fighters, two of them Pakistanis, the provincial governor said.

In other incidents, suspected Taliban fighters on motorcycles killed a government militia commander and his brother in the southern province of Helmand, and a roadside blast in the southeastern town of Khost wounded four people, two of them policemen, police said.