Officials in southern Afghanistan say a suicide bomber hit a provincial police headquarters, killing one police officer and wounding at least three other people.

Authorities say the insurgent was dressed in a police uniform when he hit the building Saturday in Lashkar Gah, the provincial capital of Helmand province.

Officials say the bomber detonated his explosives at the entrance to the building.

No group has claimed responsibility for the attack, but the Taliban has stepped up its attacks on Afghan security forces as foreign combat troops prepare to withdraw by the end of the year.