A pickup truck laden with explosives blew up outside a police station in northwestern Pakistan on Monday, killing four people in an area that has become the focal point for militant retaliation against an army offensive along the nearby Afghan border.
The explosion destroyed several shops and homes and damaged the station and a nearby mosque in the town of Badh Ber, which lies close to a Pakistani air force base as well as the major northwestern city of Peshawar. Thirty other people were wounded.
Militants have killed more than 300 civilians and security personnel in the last month to try and weaken the country's resolve to continue the military operation in South Waziristan region, where al-Qaida and Taliban leaders are believed to be hiding.
"We have to continue this war against terrorists and have to keep our nerves," said Mian Iftikhar Hussain, the information minister for North West Frontier Province where Badh Ber is located.
Police opened fire on the pickup truck as it approached a checkpoint in front of the police station, but the driver was able to detonate his explosives, said Peshawar police chief Liaqat Ali Khan.
"The sound of the blast was very loud, and when I rushed out from my home I saw everything was destroyed here," Tariq Hasan told AP Television News.
The attack killed four people and wounded 30 others, said Sahib Gul, a doctor at a hospital in Peshawar where the victims were brought. The identities of the dead were not known.
Local television footage showed rescue workers searching for survivors amid a tangle of bricks and twisted metal. The blast killed a horse that was attached to a wooden carriage and injured another nearby.
Police explosives expert Tanvir Ahmed estimated the truck was carrying about 550 pounds (250 kilograms) of high explosives, a much larger amount than has been used in other bombings carried out in recent weeks.
"This is an obvious reaction to the operation in the tribal areas," said Sahibzada Anees, a senior government official in the area.
Badh Ber is located some 7 miles (12 kilometers) south of Peshawar. The area in and around the city, which borders Pakistan's semiautonomous tribal region, has experienced a wave of attacks since the army launched its South Waziristan offensive in mid-October. More than 50 people have been killed in the area in a little over a week.
Hussain, the information minister, said the South Waziristan operation has driven many militants out of the tribal region into places near Peshawar, making the area a prime target for attacks.
"Terrorists have spread into our settled areas and have surrounded Peshawar, but they cannot defeat our resolve," said Hussain.