10 policemen killed by maoist attack in Orissa.

A powerful bomb blast in eastern India has claimed the lives of at least 10 policemen.

Another 10 policemen were injured in the attack that took place in the Koraput district of the state of Orissa on Sunday.

The police officers were killed when a landmine planted by Maoist rebels struck the vehicle they were travelling in.

"We are confirming 10 deaths, but it may go up," senior police official Sanjeev Panda told reporters.

Sources said the security personnel were on patrol as part of anti-insurgency operations.

Maoist rebels have stepped up attacks in response to a government offensive that was launched late last year.

The Maoist insurgency began as a peasant uprising in 1967 and has now spread to 20 of India's 28 states. Over 6,000 people have died in clashes over the decades.