Two policemen were killed and one was injured in an attack by Maoists in Chhattisgarh's Bijapur district today. The policemen were going out of their camp for patrolling when they were ambushed by the Maoists, the police said. The injured policemen has been admitted to a hospital and is critical, a senior officer said. The state police supported by the central police forces have stepped up the offensive against Maoists in the jungles of Chhattisgarh.