Four Central Reserve Police Force personnel, including a sub inspector, were killed on Saturday in an ambush laid by the Maoists in Narayanpur district of Chhattisgarh.

"When a CRPF party was on a combing operation, the Maoists triggered land mines blasts and opened indiscriminate firing in Brahmabeda jungle of Narayanpur district, about 275 km from the state capital," CRPF sources told PTI.

A sub inspector and three constables were killed on the spot, they said.

Additional forces have been rushed to the spot, they added. Central para-military forces have been deployed in anti-Naxal operations in all five districts