Maoist rebels in eastern India have ambushed a security convoy, killing five and wounding two others, India's home minister has said.

The soldiers were travelling through Koraput district in Odisha state early on Tuesday when the rebels set off a bomb, blowing up their vehicle. The convoy was carrying 18 personnel of the para-military Border Security Force.

Home Minister Sushilkumar Shinde said reinforcements had been sent to the remote area and a hunt had been launched for the rebels.

The Maoists in India, also known as Naxals, have been fighting in several states for more than 40 years.

They are inspired by the Chinese Communist revolutionary leader Mao Zedong and have drawn support from displaced tribal populations opposed to corporate exploitation and official corruption

They demand land and jobs for poor tribal communities that they say are ignored by the government. Prime Minister Manmohan Singh says the rebels are India's biggest internal threat.