Suicide bomber strikes district headquarters in western Afghanistan

A suicide bomber in a four-wheel-drive vehicle blew up his cache of explosives on Tuesday morning in Herat province in western Afghanistan, killing or wounding more than 20 people, authorities said.

The attacker struck as people were gathered outside a district headquarters building, waiting to go inside to see government officials about various business matters, said Nasar Ahmad Popul, the chief of the province's Guzara district.

"When a suicide bomber tried to enter the district headquarters, he was stopped by the police but then he detonated his explosives -- right at the gate," said Popul, who was inside the building at the time of the blast. "The explosion was so strong -- there are causalities among police and civilians."

Raouf Ahmedi, spokesman for the police commander of the western region of Afghanistan, said more than 20 people have been killed or wounded.

Herat province as well as most of western Afghanistan is relatively calm as insurgents have concentrated their attacks in the south and east.

The responsibility for nearly all of Herat province has been transferred, or is in the process of being transferred, from NATO troops to Afghan forces.

The attack occurred between Herat city, the provincial capital, and the main airport in the area, which is located in Guzara district.