A powerful bomb went off in a shop selling DVDs and mobile phones in the restive Orakzai tribal region of northwest Pakistan today, killing at least 12 people and injuring over 20 others, officials said.        

The bomb exploded in the shop in a market in Kalaya, the main town of Orakzai Agency, officials of the local political administration said. Initial reports had said the bomb went off near a security check post. Some officials said the attack targeted a group of Ferozkhel tribesmen who are opposed to the Taliban.        

The tribesmen had gathered in the area after Friday prayers. No group has claimed responsibility for the attack. In the past, the Taliban have targeted shops selling music and movies, which they have declared "un-Islamic".         The injured were taken to nearby hospitals. Two shops were destroyed by the blast while several more were damaged.