A suicide bomber blew himself up on Saturday after an exchange of fire with police at Kohat in Pakistan's troubled northwest, officials said.
The bomber detonated his suicide jacket after he failed to break a police cordon in Mohallah Bibi Pakdaman area of Kohat city.
Acting on a tip-off, police traced the bomber and asked him to surrender. The bomber entered a house and took an occupant hostage. While he was talking on the phone, the hostage managed to escape.
Police surrounded the house and again asked the bomber to surrender. He kept the police at bay firing at them and lobbing grenades.
Later, he blew himself up, officials said. Police have launched a search for the bomber's accomplices.