Three Pakistani soldiers were killed and three injured in a roadside bomb attack in North Waziristan tribal region on Saturday, security officials said.
The remote control bomb targeted a vehicle of the security forces at remote Datta Khel area near the Afghan border.
The injured were taken to a military hospital in Bannu, a main city near North Waziristan.
No group has claimed responsibility. The authorities blamed Taliban for such attacks.
Security officials said the security forces were on routine patrolling when their vehicle came under attack.
It is the second attack on security forces in the area in two days.
One security man was killed and another was injured in an attack on the forces on Friday.
The security forces, backed by fighter jets, are battling the Taliban and other militant groups in North Waziristan. The operation was launched in June last year after the rare peace talks with the Taliban collapsed.
The army has cleared over 90 percent areas and the military spokesman said over 2000 militants have also been killed during the offensive. Some militants have fled to other areas and crossed the Afghan side of the border, according to security officials.