NEW DELHI (AFP/ Reuters) - Maoist rebels killed 17 Indian policemen on Thursday in the western state of Maharashtra, the latest in a series of bloody assaults by the guerrillas, police said. At least 150 Maoists attacked the policemen in a forested area in Gadchiroli district of Maharashtra, police said. One senior officer and 16 constables have died, police inspector SD Mundhe told AFP. The rebels have fled to the Chhattisgarh border, Mundhe said, referring to the central Indian state where the rebels have their stronghold. We cannot search for them in the dark. The Maoists attacked the police in the gunfight that lasted more than two hours, Mundhe said. Meanwhile, senior police officials said on Thursday India plans to launch a large scale offensive against Maoist rebels in its insurgency-riddled eastern and central states, against a backdrop of rising attacks. Local media reports said the government will soon deploy tens of thousands of security forces in a crackdown that could help unlock billions of dollars of investment in Maoist-hit areas. A home ministry spokesman declined to confirm these reports, but senior police officials in three of the worst affected states told Reuters they had been asked to prepare for a strike. Everything is ready. We will launch the operation all of a sudden, but the plan will be carried out by the home ministry as per their directive, said Neelmani, the additional director general of police in eastern Bihar state. Senior police officials in Chhattisgarh said 40,000 police are on standby for an upcoming assault in remote jungle areas, and are waiting to be reinforced by elite paramilitary troops. A Maoist spokesman, who gave his name as Amarjeet Advani, said the rebels have set up camps to train cadres in guerrilla warfare and handle sophisticated weapons to counter any strikes. Singh said last month Indias campaign so far against the Maoists had failed to produce results. Indias air force has asked for permission from the government to return fire if attacked by Maoists. It is not like Rambo, Air Chief Marshal P.V. Naik said. We are only trying to protect our helicopters and our men and women who fly those helicopters.