A roadside bomb Friday killed at least two Frontier Corps (FC) personnel in Khyber tribal region, security sources said.
They said an improvised explosive device (IED) hit the patrolling party in Akakhel area of Bara Tehsil.
No group claimed responsibility. The Taliban and Lashkar-e-Islam militant groups are carrying out attacks on forces in Khyber agency, also a key NATO supply route.
The security forces are conducting operation against the banned groups in the region.
It is the second attack on security forces in the restive tribal areas.
Two soldiers were killed and four others were injured in firing by suspected militants in Bajaur tribal region.