New Delhi  - At least 20 policemen were killed when a police vehicle was blown up by suspected Maoist rebels in India's eastern state of Orissa on Wednesday, officials said.

According to a police spokesman, a 30-member team from the Special Operation Group (SOG) was surveying an area in the southern Malkangiri district for landmines when the explosion took place.

"Twenty personnel were killed as a police jeep was ripped apart in an explosion," Malkangiri Superintendent of Police GSK Das said in a telephone interview. The district lies 500 kilometres south-west of the state capital Bhubaneshwar.

"We are yet to ascertain whether it was a landmine blast or the explosion was triggered remotely by the rebels in the area," Das said.

Das added that police suspected rebels were behind the attack since the region is a hotbed of Maoist activities.

"We have dispatched additional police teams to the area who will launch a search for the rebels," he added.

The incident comes close on the heels of a major Maoist attack in the same district in which 39 elite anti-Maoist police force members were killed.

The policemen belonging to the Greyhound Force drowned in a reservoir in Malkangiri on June 29 after the boat ferrying them came under heavy gunfire from Maoists.

Wednesday's attack in Orissa came around the same time as the Indian government announced a multi-pronged strategy to deal with the Maoist insurgency in New Delhi.

Federal Home Secretary Madhukar Gupta told reporters that six jungle warfare and counter-insurgency schools would be set up to fight the rebels.

Maoist militants, who claim to be fighting for the rural poor, tribal people and the landless, operate in 13 of India's 29 states. They usually target police and government installations.

Thousands of people, mostly police and paramilitary personnel and government officials, have been killed in the insurgency since the late 1960s. (dpa)