In a daring strike, a suicide bomber blew himself up in an mess in a high-security army camp at Tarbela dam in Northwestern Pakistan, 50 km from Islamabad, on Thursday night killing at least 20 officers of an elite force and injuring 44 others.

Reports from Tarbela said the bomber from the Taliban militia targetted the elite Special Security Group unit which had taken part in the July 23 Lal Masjid operations in which scores of armed militants were killed.

Dawn TV quoted Faisal Zaman, a member of the Provincial Assembly to say that 20 officers were killed and 44 injured.

Pakistan Defence Spokesman Maj Gen Waheed Arshad confirmed the death of 15 personnel but declined to specify whether the attack took place on the SSG unit.

The attack comes ten days after two suicide bombings ripped through a military bus carrying defence ministry employees and a busy market near Pakistan's military headquarters in the garrison town of Rawalpindi killing 25 people and injuring 68 others.

Top intelligence officials said it was a suicide attack and that the victims belonged to the army's Karar commando group, which has participated in operations against militants in various parts of the country in recent years including at the besieged Lal Masjid.

The blast also disrupted the communication system in the region and the security forces cordoned of the area after the blast.

Dawn News TV quoted local government officials as saying that 20 SSG personnel were killed and 44 injured.

Tarbela is a large dam built on the Indus River. The SSG officers mess was located in a high security cantonment area where the security was stated to be tight.

It is not yet clear how the bomber blew himself up in the midst of officers who were having their dinner.

The explosion apparently took place around 2000 IST just as the mess was full of personnel having their dinner after the evening prayers.

The blast at the camp came as the military said it killed 70 militants in two days of intense fighting in tribal areas bordering Afghanistan.

The violence also coincides with the visit of US Deputy Secretary of State John Negroponte.