PARACHINAR, Pakistan (Reuters) -- A suicide car bomber has killed three policemen and a child in an attack on a police station in a northwestern Pakistani town, police said.
Al-Qaeda-linked Pakistani militants have carried out numerous attacks on members of the security forces over the past couple of years, and they stepped up strikes after the army launched an offensive on their main bastion in October.
The blast in the town of Karak, 200 kilometers southwest of Islamabad, came as police were on the alert for attacks on religious processions to mark the anniversary of the Prophet Muhammad's birth.
"The blast destroyed part of police station and a nearby mosque," police official Gul Sadi Khan told Reuters, adding three policemen had been killed. "Thirteen people have been wounded and we fear more people are trapped under the debris."
Another police official said a child passer-by had also been killed.
Karak is in North West Frontier Province, which has borne the brunt of attacks over the past year.
The Pakistani Taliban, allies of the Afghan Taliban, have lost much ground in army offensives over the past year.
They were pushed out of the Swat valley, northwest of Islamabad, and in October the army began a big offensive in the militants' South Waziristan bastion on the Afghan border.
Pakistani action against militants on the border is seen as crucial for efforts to bring stability to Afghanistan, where U.S. forces are spearheading one of NATO's biggest offensive against the Afghan Taliban.
Fifty-seven people were killed in Karachi in a militant attack on a Muslim congregation marking the holiday in 2006.