However, there is no information on any casualties or injuries in the ambush, they said.
"The joint squad of Chhattisgarh Armed Force (CAF) and district forces recovered two unexploded tiffin bombs, weighing five kgs each, following a massive gun-battle with ultras under Antagarh police station limits," a senior police official told PTI.
The patrolling party was engaged in the area domination exercise to ensure protection to under-construction road in the region, located around 250 kms away from the state capital Raipur when a group of rebels triggered a landmine blast, he said.
"Immediately jawans launched retaliatory attack breaking the ambush and begun encircling naxals. The exchange took place for about half an hour. The Naxals retreated as the police were fast zeroing in on them", the official said.
Besides bombs, police also found detonators and wire from the spot, he said, adding the explosives were later defused.