Four people, including a Maoist guerrilla, were killed and two security personnel were injured in three separate incidents of Maoist violence in Jharkhand, police said Friday.

Two Central Reserve Police Force (CRPF) troopers were injured early Friday when Maoist guerrillas fired at a patrolling party in Porahat jungle of West Singhbhum district, around 170 km from here. The security personnel returned fire and a rebel was killed, a police official said.