In a major operation against the left wing extremism, security forces gunned down 31 Maoists during a fierce encounter in Chhattisgarh's Bijapur district on Sunday, police said.

Two security personnel were also killed and as many others injured in the face-off, they said. More than 650 security personnel entered the Indravati National Park area from different sides and eliminated 31 Maoists  in their den, Chhattisgarh's Deputy Chief Minister Vijay Sharma said.