The CRPF contingent, which lost 27 of its men while returning after having escorted their colleagues going on leave, were fired upon by heavily-armed Naxalites from treetops and nearby hillocks in Chhattisgarh's Narayanpur district on Tuesday.
"We had no inkling about the presence of Maoists," said an injured CRPF jawan recuperating at a hospital.
The Maoists, who had climbed trees and nearby hillocks, fired upon the jawans with automatic weapons as they walked back to their camp.
The jawan said the contingent made valiant efforts in fighting back the Naxals for over two hours resulting in casualties among the Maoists.
He, however, could not say how many Maoists were killed.
"We are always ready as we know that encounters can happen anytime and I think that is why we could give them a tough fight and inflict more damage on them than they did to us," the jawan said.
He said some of the Naxals sitting on a tree started firing, diverting their attention.
Another jawan Parmanand had earlier said that the Naxals numbering around 200 were in battle fatigue and armed to the teeth.
Parmanand said he tried to evacuate some of his wounded colleagues and secure the weapons of the martyred personnel, but he himself got injured after being hit by four bullets.
As additional personnel arrived at the spot, the Naxals started retreating while continuing to fire, he said.