The clash marked the latest violence in an escalating fight between security forces and the Maoists, who are active across a swathe of northern and eastern India.

"Six Maoists were killed on Saturday in the Banka district by security forces, and one Maoist has been arrested," senior police officer Rajyavardhan Sharma told AFP. Violence by Maoist rebels in India rose in 2010, leaving a record 1,169 people dead, federal government figures show.

Last week, Maoist rebels in the state of Orissa freed two government officials after striking a controversial deal with state authorities to release five Maoists.

The extreme left wing movement, which began in 1967, feeds off land disputes, police brutality and corruption, and is strongest in the poorest and most deprived areas of India, many of which are rich in natural resources.