Peshawar - A suicide bomber detonated a car in an alley behind a police station in a strategically vital town in northwest Pakistan on Monday, killing at least 17 police and civilians in an explosion that shattered the station and neighbouring homes, police said.

About 40 people were wounded in the attack in Lakki Marwat, which sits on the main road and rail link between Punjab Province, Pakistan's largest and most prosperous, and the North and South Waziristan tribal regions.

A Pakistani army offensive pushed many militants out of South Waziristan in October. The militants still control much of North Waziristan, where US drone aircraft have been conducting a campaign of targeted killings.

Police official Liaquat Ali said 45 police were in the building when the bomber struck.