At least 15 Pakistani soldiers have been killed in a suicide bombing in the canteen of a building used by the army's elite Special Services Group. It's the second major attack on a sensitive army unit this month. The blast occurred in the town of Tarbela Ghazi, around 70 km (44 miles) northwest of the capital Islamabad. President Pervez Musharraf, who is also army chief, has also served in the Special Services. A security official, on condition of anonymity, revealed the bomber blew himself up in the canteen when the soldiers were having dinner. Police were on guard outside the army camp. Police official Javaid Iqbal said they'd been told between 15 and 20 people were killed and as many again wounded. 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 intelligence agency of the army, were killed in twin suicide attacks in Rawalpindi garrison town, adjoining Islamabad. Officials said evidence pointed to the involvement of al Qaeda-linked militants. 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 Taliban militants. Speculation is rife in Pakistan that Musharraf might impose emergency rule in the country by using the pretext of militant attacks in view of his growing political problems. Parliamentary elections are due in the country by the end of the year.