By Subir Bhaumik
BBC News, Calcutta
**Indian security forces have stepped up their operations against Maoist rebels, officials say.**Thousands of newly-arrived federal forces have joined those already in ground in three eastern states where rebels have a formidable presence.
A major security offensive -Operation Green Hunt- to flush out the rebels is already underway in several states.
More than 6,000 people have died during the rebels’ 20-year fight for communist rule in many Indian states.
The rebels now have a presence in 223 of India’s 600-odd districts.
Prime Minister Manmohan Singh has described the Maoist insurgency as India’s “greatest internal security challenge”.
The newly-arrived federal forces are now moving into the jungles of West Bengal, Orissa and Jharkhand states that may house a number of rebel hideouts.
West Bengal police chief Bhupinder Singh said 6,000 new forces had arrived in the state’s Purulia and West Midnapore districts, which have seen rebel violence.
In neighbouring Jharkhand state, police chief Neyaz Ahmed said that federal forces along with local armed police had begun attacking rebels hideouts in the jungles.
“We have seized a lot of explosives and destroyed a few rebel camps,” he said.
With chances of peaceful negotiations with the government fading, the Maoist military wing chief Koteswara Rao has threatened to attack targets in the cities of Bengal and Orissa.
Mr Rao said his offer of a 72-day ceasefire with government forces stands. He has also named three “intellectuals” to mediate between the government and the rebels.
The federal government has not reacted to the latest demand of the rebels, and called some of their demands “bizarre”.