A powerful explosion in Pakistan's northwestern city of Peshawar on Saturday left at least seven police officers wounded amid rising instability in the area. Officials said the attack took place as the policemen raided suspected militant hideouts in the city's outskirts.
They added that a militant commander who feared being arrested threw a hand grenade at the officers.
A brief shootout also reportedly broke out shortly before the explosion.
Police have tightened security around the area and are investigating the incident.