A lieutenant colonel was among six Pakistani soldiers killed when the vehicle they were travelling in was targeted with a roadside bomb in Yakh Kandao area of Orakzai tribal agency, TV news channels said, adding two other security personnel were seriously injured in the attack.
The injured were taken to a hospital in Kohat, the main city in the area.
Orakzai is considered a stronghold of Tehrik-e-Taliban Pakistan and the militants regularly target security forces and pro-government tribal elders in the area. Al-Qaeda is also active in the region.
Additional security forces were sent to the area where the blast occurred.
In another attack, a blast ripped through a mosque packed with Friday worshippers on the outskirts of the northwestern Pakistani city of Peshawar, killing three people and injuring 20 others.
The incident occurred at the mosque situated in Pishtakharra area when worshippers were offering prayers, 'Dunya News' reported.
Khyber Pakhtunkhwa Information Minister Mian Iftikhar Hussain termed the terror attack as a reaction to the ongoing military offensive against militants in the country's restive northwest.
Police said 1.5 kilogram of explosives were used in the attack. Preliminary reports said the bomb was planted at the mosque's verandah.
No group has so far claimed responsibility for today's bomb attacks in Orakzai and Peshawar.
Separately, at least three men were injured when two groups opened fire at each other at PIMS Hospital in Islamabad, 'Geo News' reported.
It quoted unnamed sources as saying that two groups clashed at the Hospital over an old family dispute. The gunmen managed to flee crime scene, the report said.