The head of the local public health office Amir Badsha Mangal said that nine people were dead and 40 people were injured, four of whom were in a serious condition.

Local police chief Abdul Hakim Eshaqzai said that women and children were among the dead. Hospitals in the city have been "overwhelmed" by the influx of wounded people, he added, warning: "The casualty toll will possibly increase."

Eshaqzai blamed the attack on "the enemies of the people and government of Afghanistan," a phrase often used by officials to refer to the Taliban. The bomb was carried in a Toyota van, he added.

Taliban spokesman Zabihullah Mujahid told AFP that the militants, battling international forces in Afghanistan since being ousted from power in 2001, were responsible.

"The bomber has attacked the second police district headquarters and has also destroyed four police vehicles in the attack," he said.