Pakistani officials say three soldiers were killed when a roadside bomb exploded near a team of bomb disposal experts in a remote area near the Afghan border.
Government administrator Kamran Afridi said the December 24 blast took place in the village of Ghulam Khan in North Waziristan, one of the country's seven semiautonomous tribal areas where the military has been battling Islamist militants, including the Pakistani Taliban.
The soldiers from the paramilitary Frontier Corps were clearing a road for the passage of a security convoy, the official said. Local intelligence officials confirmed the incident and casualties.
No one immediately claimed responsibility for the blast.
An unnamed senior security official was quoted by the AFP news agency as saying a curfew has been imposed in the area as security forces search for the suspected militants who planted the bomb.
The account cannot be independently verified as the area is out of bounds for media.