There has been a surge in Maoist violence in recent months
India's Maoist rebels have again demanded the release of their senior leaders as a precondition for beginning talks with the government.
Maoist military wing head Koteswara Rao's demand comes a day after the arrest of Venkateswar Reddy, alias Telegu Deepak, in Calcutta.
Mr Deepak is is believed to have masterminded numerous attacks and is a close associate of Mr Rao.
He is the latest of several senior Maoists to be arrested.
In September another senior Maoist, Kobad Ghandy, was arrested in Delhi.
In October police also arrested a husband and wife - who they said were senior Maoist leaders - in the state of Jharkhand.
Last month, Mr Rao offered a ceasefire ahead of possible talks with the government - but only if it called off an offensive against the rebels.
The government asked the rebels to give the offer in "writing". The rebels responded by giving out a telephone number to the government to call so that negotiations could begin.
A spokesman for Mr Rao said that the rebels would now launch an offensive if the government did not free its leaders.
"If the government does not inform us in the next three days about how they want to proceed on our offer, we will abandon all peace efforts and unleash a full scale offensive," Maoist spokesman Comrade Raju told the BBC over the telephone from an undisclosed hideout.
Home Minister P Chidambaram in December that said he was ready for "serious negotiations" with the rebels.
He said that they were not "terrorists" and had raised "serious issues" about the lack of development.
Police say that Mr Deepak planned last month's attack on a camp of the Eastern Frontier Rifles, in which 24 paramilitary soldiers died.
They say that he was a member of the Central Military Commission of the Communist Party of India (Maoist).
The BBC's Subir Bhaumik in Calcutta says that he is easily one of the biggest catches in the anti-Maoist offensive - Operation Green Hunt - currently under way in several states.
Our correspondent says that the arrest comes against the backdrop of the apparent failure to get negotiations started between the Indian government and Maoist rebels after both sides put forward their conditions for talks.
More than 6,000 people have died during the rebels' 20-year fight for communist rule in many Indian states.
Prime Minister Manmohan Singh has described the Maoist insurgency as India's "greatest internal security challenge".
The rebels now have a presence in 223 of India's 600-odd districts.