A Chhattisgarh Armed Force (CAF)jawan was on Wednesday injured in an encounter with Naxals in Narayanpur district of the state, police said.The gun-battle took place at around 11 am when a joint team of security forces was was out on patrolling to ensure security to a road construction work under Chhotedongar police station area, located around 350 kms from capital Raipur, a police official told PTI."The personnel belonging to the CAF and district force were involved in the operation launched from the police camp in Aamdai valley," he said.When the security forces were advancing through forest adjacent to Aamdai Ghati hill, an exchange of fire broke out between the two sides, he said.However, the ultras fled from the spot after a brief gun-battle, he added."Head constable Anand Bhagat, belonging to CAF's 9th battalion, sustained bullet injuries in the gunfight", he added.The injured jawan was being airlifted to Raipur for treatment, the official said adding that a search operation was underway in the area.