“The bomb was planted on the roadside. No policeman was injured in the blast,” Sariab SHO Ehsanullah Marwat told Aaj News.

The blast was reported hours after a bombing targeting a police vehicle in a marketplace in Quetta killed four people and injured 18.

Initial reports showed an improvised device containing one-to-two kilogrammes of explosives was planted on the roadside near the vehicle and detonated remotely, the police said.

SHO Marwat said he was in the car at the time of the explosion. The bomb disposal squad was inspecting the site of the blast.