Three CRPF personnel, including an officer, were killed in a landmine blast triggered by Maoists in Orissa's southern district of Malkangiri on Friday. Seven others were also injured in the blast.

The blast took place in Maoist-dominated MV-66 area, about 40 km from here, when a van carrying the CRPF personnel was on its way from Kalimela to Gompagunda probably to pick up rations, Malkangiri Superintendent of Police Satyabrata Bhoi said.

The landmine was planted at a culvert and exploded when the van passed over it, he said.

CRPF deputy commandant Bhupinder Singh was among the three CRPF men killed.

The attack is believed to be part of the Maoist strategy to restrict movement of security forces ahead of their proposed offensive in the region.

Additional CRPF jawans and state police personnel have been rushed to the site, while steps taken for intensifying patrolling in the area, Bhoi said.

This was the third attack by Maoists in Malkangiri this month. A guest house of a private steel company in Chitrakonda area was torched and a bridge over a rivulet was blown up on the other two occasions.