Lalgarh, Aug 18 - A central paramilitary trooper died in an accidental grenade blast in this area of West Bengal's West Midnapore district Tuesday, police said.

'The jawan was cleaning the hand grenade when it went off,' West Midnapore district magistrate Narayan Swarup Nigam told IANS, adding the trooper died on the spot.

The Central Reserve Police Force (CRPF) trooper was posted in one of the security forces' camps in the area, said state Director General of Police Bhupinder Singh.

Another CRPF trooper, Chalanta Kumar Roy, who suffered a bullet wound in the chest during an exchange of fire with the rebels Monday, has been shifted to a Kolkata hospital. 'He is stable,' said Nigam.

The West Bengal government has launched a massive joint operation of central paramilitary forces and state armed police in and around the Lalgarh area to flush out Maoist rebels, who had created a virtual 'free zone' since last November by torching police camps and killing cadres of the state's ruling communist party besides driving out the civil administration.