A bomb attack in a  town in northwest Pakistan has killed at least 18 people and injured several others.

The device ripped through a market in Kohat, police said.

Wednesday's blast in Tira, the main bazaar in the garrison town, also damaged 30 shops.

The injured are being shifted to hospital.

Fazal Naeem, a police spokesman said "the bomb was apparently planted in a vehicle parked at the main bus stand."

No group has claimed responsibility for the attack as yet.

Police said it was a suicide attack but the target is not yet clear. 

Source: Al Jazeera and agencies