Four persons, including two CRPF personnel, were injured in a grenade attack in Pulwama district of south Kashmir on Saturday, the police said. Militants lobbed a grenade at a CRPF party in Batagund area of Tral, a police official said. Four persons, including two CRPF jawans, were injured in the incident, he said. The area has been cordoned off and a search operation is underway, the official said.