The incident took place in the forests of Gangaloor police station area when a team of CRPF's elite CoBRa unit was carrying out a search-cum-area domination operation in the region, a CRPF official said.
Security forces were outon the operation since last evening to the interior forests of Gangaloor, located around 450 km away from the state capital.
When they reached Pusnar at around 9:30 am today, Naxals detonated the Improvised Explosive Device leaving a constable injured, he said.
"The constable identified as Arun Minj sustained injuries in his eye and left leg," the official said, adding that he was admitted to a local hospital.