HANGU: Four persons were injured in a hand-grenade attack in the limits of Doaba Police Station on Tuesday, police said. They said four persons identified as Amin Sharif, Bahadur Zaman, Raid Gul and Ismail Khan were chitchatting in Sarozai village when one Suleman allegedly hurled a grenade, leaving them injured. The injured were shifted to a hospital while the police arrested the accused and started an investigation after registering a case.