At least 15 Pakistani soldiers were killed on Thursday in a suicide bombing at an army building near the capital Islamabad, the military said, the second major attack on the army this month.
The blast occurred in the canteen of the building used by the army's elite Special Services Group (SSG) in the town of Tarbela Ghazi, around 70 km (45 miles) northwest of Islamabad.
President Pervez Musharraf, who is also army chief, served in the SSG.
"It was a suicide attack. The bomber blew himself in the canteen when the soldiers were dining," a security official said on condition of anonymity.
Military spokesman Major-General Waheed Arshad said 15 soldiers were killed and a government official said the toll could rise as several soldiers were critically wounded.
Earlier this month, 25 people, most of them staff members of an army intelligence agency, were killed in twin suicide attacks in Rawalpindi garrison town, adjoining Islamabad.
Officials said evidence pointed to the involvement of al Qaeda-linked militants who are battling security forces in the tribal region near the Afghan border in those attacks.
Pakistan has seen a wave of bomb and suicide attacks since an army assault in July on Islamabad's Red Mosque, known for its links with the Taliban militants.
More than 250 people, most of them members of security forces and police, have been killed in these attacks.
The security forces have killed up to 70 militants in battles in Waziristan tribal region over the past two days.
The latest violence coincided with the visit of US Deputy Secretary of State John Negroponte to Pakistan.
Musharraf, a staunch ally of the United States, is facing a deepening political crisis as he prepares to run for another term in office in the coming weeks.
Musharraf, whose authority has eroded since his unsuccessful attempt to sack country's chief justice in March, is under tremendous international and domestic pressure to quit his powerful position of army chief before he runs for re-election.
Speculation is rife in Pakistan that Musharraf might impose emergency rule in the light of his growing political problems by using the pretext of militant attacks.
Parliamentary elections are due by the turn of the year.
Despite growing concern over Musharraf's hold on power, Negroponte praised Pakistan's campaign against terrorism in its own backyard and said Washington was committed to a long-term relationship with Islamabad.
Musharraf told Negroponte there should never be any doubt in Pakistan's commitment to fighting extremism and militancy as "it was in its own national interests".