Thursday's blast came hours after John Negroponte, the visiting US deputy secretary of state, met Pervez Musharraf, Pakistan's president, in Islamabad.
After meeting Negroponte, Musharraf reaffirmed "Pakistan's firm resolve to fight extremism and terrorism".
"Musharraf is shouting slogans of war against terror in order to win US support"
Ali Abu Hamza, Chichawatni, Pakistan
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Negroponte led a delegation aimed at developing long-term business, energy, education and defence ties with Pakistan, but he was also accompanied by Dell Dailey, US ambassador at large and counter-terrorism co-ordinator.
The bombing was the latest in a series of attacks targeting Pakistan's army.
Major-General Waheed Arshad, an army spokesman, said that 15 soldiers were killed and 11 wounded, some seriously.
The Tarbela facility, about 100km south of the capital, Islamabad, is the headquarters of a counter-terrorism quick reaction force.
Two security officials speaking on condition of anonymity said the bomber rammed an explosives-laden vehicle into a canteen where dozens of soldiers were eating.
The victims belonged to the army's Karar commando group, which has participated in operations against Islamic fighters in various parts of the country, they said.
The group took part in the army raid against pro-Taliban fighters in Islamabad's Red mosque in July that left over 100 dead and triggered a spate of reprisal attacks against security forces, Geo reported.
Meanwhile, armed men on motorcycles killed at least six people when they attacked a bus in the southern city of Karachi with a hand grenade and gunfire.
| Four of the dead on the bus were from the |
student wing of Jamaat-i-Islami [AFP]
Four of the dead were from the Islami Jamiat Tulaba (IJT), the student wing of the Jamaat-i-Islami party.
Mohammed Danish, a spokesman for the IJT, blamed the rival Mutahida Qami Movement (MQM) for the attack, although he did not offer any evidence to back up his claim. MQM mainly represents Urdu-speaking migrants in Karachi.
Jamaat-i-Islami is Pakistan's largest Islamic party. Azhar Faruqi, the city's police chief, called the attack an "act of terrorism" but provided no further details.