PESHAWAR, Pakistan -- A car bomb exploded outside the women's waiting area of a government office in Pakistan's troubled northwest tribal region on Monday, killing at least 12 people and wounding 45 others, government officials said.

The bombing apparently targeted the office of the assistant political agent for the Khyber tribal area, one of the top local government officials, said Hidayat Khan, who works in the office. The office is located in Jamrud, the main town in the Khyber tribal area.

The death toll is expected to rise, said Rehman Shah, a government official in the northwest city of Peshawar. Twelve of those wounded by the explosion were in critical condition, he said.

Local TV footage showed several cars badly damaged outside the office. Residents threw buckets of water on burning vehicles as rescue workers transported the wounded to the hospital.

No group immediately claimed responsibility for the bombing.

Khyber is home to various Islamist militant groups, including the Pakistani Taliban, which have waged a bloody insurgency against the government for the past few years.

The army has carried out offensives against the Taliban in most parts of the tribal region, including Khyber, but militants continue to carry out regular attacks in the country.

Ten Taliban militants attacked the military side of an international airport in Peshawar on Saturday night with rockets and car bombs, killing four people and wounding over 40 others. Five of the militants were killed during the attack, and five others died the next day in a gunbattle with security forces.

Also Monday, gunmen killed a provincial government spokesman in the southwest Pakistan in an apparent sectarian attack, and then shot to death two nearby policemen, police said.

The attackers shot dead Khadim Hussain Noori in Quetta, the capital of Baluchistan province, said local police official Hamid Shakeel. Noori was the provincial spokesman and also a Shiite Muslim.

As the gunmen were speeding away on a motorcycle, they killed two policemen and wounded a third, said Shakeel.

Baluchistan has experienced a spike in sectarian killings in the past year as radical Sunni Muslims have targeted Shiites, who they consider heretics.

The province is also the scene of a decades-long insurgency by Baluch nationalists who demand greater autonomy and a larger share of the province's natural resources.

Associated Press