Islamabad- A suicide car bomber attacked a security post in Pakistan's restive North-West Frontier Province on Monday, killing at least five people, police said.

The bomber rammed his vehicle into the checkpoint manned by paramilitary troops in the lawless town of Darra Adam Khel, just 40 kilometers south of the provincial capital Peshawar.

One soldier and four passersby were killed in the blast, a local police official said on condition of anonymity. At least a dozen people, mostly civilians moving on the road, also were wounded.

The official feared that the death toll could rise as some of the injured were in a critical condition.

No group immediately claimed responsibility for the attack, which came as troops backed by aircraft battled Taliban militants in the Swat valley in the same province.

Security forces sealed off the area around the bombing site and suspended traffic on roads leading out of the town, including a key tunnel connecting the north-western region with the country's southern parts.

Darra Adam Khel, known for its illegal arms industry, adjoins Pakistan's tribal region which is considered a hotbed of al-Qaeda and Taliban militants.