Maoists killed three local CPI-M leaders by thrusting rifle barrels in their mouth and pressing the trigger at a village near Lalgarh in West Midnapore district, officials said on Wednesday.

Tribal leader Chhatradhar Mahato, who was remanded to police custody till October 1, has been charged with sedition and booked under various sections of the Unlawful Activities Prevention Act and Indian Penal Code.

Tribal leader Chhatradhar Mahato, who was arrested on Saturday near Lalgarh where he had been leading an agitation against alleged police excesses since November, 2008 was remanded to police custody by a special court till October 1.

The CPI-M office at Inayatpur resembles an army bunker now. Monday night's gunbattle began after nearly 10,000 tribals led by Maoist leaders surrounded the building around 5 pm and threatened a raid.

Seven people have been reportedly killed and one person hospitalised after fresh exchange of fire between armed Maoists and CPI-M cadre in the West Midnapore district of West Bengal on Monday night.