At least three Afghan police officers have been killed in a car bombing in the southern province of Kandahar, officials say.

Twenty other people were reported wounded in the July 8 attack in the Shah Wali Kot district, including the district police chief and civilians.

There was no immediate claim of responsibility for the predawn blast, which damaged the district police headquarters and the nearby administrative office, according to provincial governor spokesman Ahmad Bahir Ahmadi.

Ahmadi said there was prior intelligence information about a plot to attack the police headquarters.

The suicide bomber was shot by security forces before he could reach his target, but the explosives detonated, the spokesman said.

Taliban fighters are active in Shah Wali Kot district.

Afghan authorities and the Taliban are preparing to engage in direct negotiations aimed at putting an end to the nearly two-decade-old war in Afghanistan.

But officials have blamed the Taliban for killing hundreds of security personnel and civilians in recent weeks, following a three-day cease-fire at the end of May.

The Taliban has denied responsibility for many attacks but has acknowledged targeting Afghan security forces in rural areas.

With reporting by dpa