Two persons were killed and three others injured as two bombs went off in the Khyber tribal region of northwest Pakistan on Wednesday, police said.
The first blast was caused by a roadside bomb in Jamrud area of Khyber Agency this morning, police officials and witnesses were quoted as saying by TV news channels.
A passer-by was killed by the explosion.
Within an hour, the second blast occurred in the same area near a check post manned by the Khasadar militia.
One member of the militia was killed and three more were injured.
The injured were taken to a hospital in Peshawar, the capital of Khyber-Pakhtunkhwa province.
No group claimed responsibility for the blasts.
Security officials said a preliminary investigation had revealed that the second blast was triggered by remote control.
Security personnel blocked roads for a while and kept people away from the site of the attack.
Several militants groups, including the Tehrik-e-Taliban Pakistan and Lashkar-e-Islam, are active in Khyber Agency, the main supply route for NATO forces in Afghanistan.