Two people were injured in a hand grenade explosion in capital city Quetta of Pakistan’s southwest Balochistan province on Tuesday, police said.

The incident happened when an unknown militant hurled a hand grenade at a police check post, before fleeing the scene with his accomplice on a motorbike, the Quetta police said.

The police remained safe in the attack. However, two passersby got injured in the incident, the police added.

The injured civilians were shifted to a nearby hospital and their condition is stable, the police said.

The area has been cordoned off for investigation and a search operation has been kicked off in the area to nab the on-the-run militants.

No group has claimed responsibility for the attack yet.