A suicide bomber struck at a hotel in a busy market in the restive North West Frontier Province on Thursday, killing at least 11 people and injuring over 20 others, most of them militants opposed to Pakistan's top Taliban [Images] commander Baitullah Mehsud.

The bomber struck at a hotel at the busy Jandola Bazar in Dera Ismail Khan, while scores of anti-Taliban militants were just beginning their meals, TV channels quoted officials as saying.

Officials said the roadside restaurant's visitors at the time included some two dozen militants opposed to Pakistani Taliban leader Baitullah Mehsud. They were members of the 'Turkestan Bittani' group. However, their leader was not in the group.

The area has been a scene of widespread sectarian killings. Witnesses said the blast killed 11 people and injured over 20 others. Officials said the death toll could rise as some of the injured are in a serious condition.

Most of the injured were taken to hospitals in nearby areas as Dera Ismail Khan did not have adequate medical infrastructure to cope with the casualties.

No group has claimed responsibility for the attack.