The attack took place when a CRPF patrol party was returning from duty in the naxalite-infested Mukrana Forest in the district between 6 to 7 am.
The death toll is likely to increase as a heavy gunbattle between the troops and the rebels was still on when reports last came in
Sources said the CRPF patrol party was taken by surprise by the naxals, who opened fire at them from nearby hillock.
The intensity of the attack can be gauged from the fact that security personnel were unable to lift the body of their colleagues killed in the ambush as extremists continued relentless firing.
A chopper has been sent from Jagdalpur, headquarters of Bastar district, to move the injured troopers to hospital. A strong contingent of state police force has also been rushed to the attack site.
Meanwhile, emergency services at the Jagdalpur hospital has been pressed into service to receive dead bodies and provide immediate relief to the injured troopers. (ANI)