PATNA, India: Maoist rebels killed six policemen Friday in a landmine attack in the eastern Indian state of Bihar in their second deadly attack on security forces in recent weeks, police said.

"The Maoists targeted a convoy heading out on patrol duty, killing six policemen in Gaya district," district police chief N. H. Khan told AFP.

A village elder and a police informer who were travelling in the same vehicle as the policemen were also killed in the explosion, Khan said.

The attack is the latest in a simmering conflict that pits the insurgents against local and national authorities in the forests and rural areas of mainly central and eastern India.

The rebels shot dead seven policemen on January 7 in the neighbouring state of Jharkhand, another hotbed of left-wing extremism.

The guerrillas, who say they are fighting for the rights of tribal people and landless farmers, often collect funds through extortion and protection rackets.

The government describes the Maoists as the country's most serious internal security threat.