A roadside bomb killed as many as 14 Pakistani soldiers in the northern border region of North Waziristan.
The bomb exploded a day after the Pakistani Taliban leader called for attacks on the military in the area to stop.
The explosion occurred on a road about 50km south of the provincial capital of Miranshah.
Up to 21 soldiers were wounded in the attack, senior army officials said.
Hakimullah Mehsud, the leader of the Pakistani Taliban, had circulated a leaflet calling for an end to the Taliban's infrequent attacks on Pakistani soldiers in North Waziristan.
Thousands of Pakistani soldiers are stationed in North Waziristan.
The ceasefire did not apply to the rest of the country, where there are often fierce clashes between the Taliban and security services.
The mountainous tribal region of North Waziristan along the Afghan border is a key stronghold of the Taliban and Al-Qaeda.
South Waziristan is under the control of the Wazir tribe, who have a peace deal with the Pakistani military.
Refusing to bury dead
Separately, Shia Muslims protesting over one of Pakistan's deadliest sectarian attacks called off their three-day sit-in after Prime Minister Raja Pervez Ashraf visited them and agreed to some of their demands.
Mr Ashraf told leaders from the Shia Hazara community that the federal government had sacked the chief minister of Balochistan province, one of the protesters' main demands.
Thousands of the Shia Hazara community, the ethnic group targeted by the blast, have been holding vigils at the site of the blast beside the 96 shrouded bodies.
They have spent two nights outside in the cold and rain and are refusing to bury their dead until their safety is guaranteed.
Islamic tradition demands that the dead be buried as soon as possible, and leaving the bodies of loved ones above ground for so long is a potent expression of grief and pain.
