At least 25 people were injured in an explosion near the Ganj Mandi police station in Rawalpindi on Sunday.
According to the rescue officials, 22 victims were shifted to the District Headquarters Hospital, while three were provided first aid on the spot.
Rescue officials said that the explosion occurred at a filtration plant situated across Ganj Mandi police station.
The area has been cordoned off and officials of the Counter-Terrorism Department and forensic experts have arrived on the scene for detailed investigations.
Initially, it was thought that a cylinder exploded however Initial reports suggested that it was a hand grenade attack.
However, the City Police Officer (CPO) Rawalpindi Mohammad Ahsan Younas said that it was too soon to ascertain the nature of the blast and further investigations are underway.