Governor Assadullah Khalid survived the attack in the heart of the city. A spokesman for the Nato-led peacekeeping force in Afghanistan said none of the Canadian troops was hurt.

"The target of the attack was the governor," Khalid's spokesman, Dawud Ahmadi, said, adding that four people had been killed and 13 wounded.

Taliban spokesman Qari Mohammed Yousuf called Reuters from an undisclosed location to claim responsibility for the latest in a series of suicide attacks in Kandahar over the past few months.

Two days earlier a suicide car bomber killed three civilians and himself on a road outside the city.

In neighbouring Zabul province, Afghan army troops killed four Taliban fighters and captured three hiding in a village in the Shah Joy district.

And in Paktika, another southern province, a local government health official was shot dead with his brother on his way to work on Saturday. Officials could not identify the killers.

The attacks come during the bloodiest phase of a Taliban-led insurgency that has raged since US-led coalition forces overthrew the militants' radical Islamic government in 2001.

More than 900 people have been killed in the insurgency since the start of the year, half of them in May.

A rise in Taliban activity in the south coincides with preparations for Nato-led peacekeepers to take control of southern provinces from coalition forces, who have had a more offensive mission to hunt down Taliban and al-Qaeda remnants.