The explosion took place in Temelwada forests under Chintagufa Police Station limits while a ROP (Road Opening Party) of Central Reserve Police Force's 223rd battalion was carrying out its route clearing task on Dornapal-Chintagufa axis, a senior police official told PTI.
As the CRPF personnel were cordoning off forests, 3 km away from Temelwada, the Naxals detonated an improvised explosive device (IED) blast at around 11 AM, leaving ASI Shiv Prasad and constable Pradeep injured, he said.
Subsequently, firing also broke out between the security personnel and the rebels which lasted for a short period following which Naxals fled into the forest, he said.
"The condition of constable Pradeep was stated to be critical," he said.
A combing operation has been launched in the region to nab the attackers, he added.