Ten people, including seven security personnel, were injured when militants triggered an improvised explosive device near an army truck in the northwestern Pakistani town of Kohat on Tuesday.
The army closed the nearby Kohat tunnel in the North West Frontier Province as security forces launched a search operation in Darra Adam Khel and other areas following the blast.
The IED exploded near a truck carrying Frontier Corps personnel which was heading towards Parachinar, the headquarters of Kurram Agency.
The attack comes two days after a suicide bomber blew himself up in a crowded market within the cantonment area of the north-west Pakistani town of Mardan, killing 13 people and injuring 22 others.
The Taliban militants in Pakistan had claimed responsibility for the attack in Mardan, calling it a revenge strike against US-led military operations in the NWFP.