Bihar government today said it would further intensify anti-Maoist operations and rescue searches for the four abducted policemen, even as Maoists set an ultimatum to release their eight jailed cadres by tomorrow failing which they would kill all the captives.

"I want to clarify at this stage that we will further intensify the operations against the Maoists and also for rescuing the policemen from them," DGP Neelmani told reporters.

Neelmani said the state government had not not received any ultimatum officially from the Maoists in this connection.

"Only the media have reported the Maoists' ultimatum... and it may or may not be true," he said.

Operations have been launched by combined forces of the CRPF, BMP, Special Task Force of Bihar Police in hilly terrains in Lakhisarai and its adjoining Jamui and Munger districts, besides elsewhere for rescuing the policemen.

Neelmani said he also had a meeting with CRPF Director General Vikram Srivastava where it was decided to launch a combined offensive against the Maoists.

"We will not allow the sacrifice caused by the policemen in the encounter to go waste... They were brave and we will ensure to counter the Maoists," Srivastava added.

We have taken a lesson from the Lakhisarai incident and are evolving strategic measures to fight the Maoists, the DGP said.

The Maoists today issued an ultimatum to Bihar government to release eight of their jailed commanders by tomorrow, failing which they would kill four securitymen abducted by them from Lakhisarai district.

The four who were held captives are sub-inspectors Rupesh Kumar and Abhay Prasad Yadav, Lucas Tete (BMP jawan) and Ehtesham Khan (BMP Havildar).

Avinash, a self-proclaimed spokesman of Maoist, told reporters in Munger over phone early this morning that they had communicated their demand to Chief Minister Nitish Kumar's official residence in Patna.

He also claimed responsibility for killing of seven policemen during the encounter on Sunday and abduction of the securitymen.

"Eight of our commanders lodged in jails of Bihar should be released otherwise we will be compelled to kill the four policemen - two sub-inspectors and two Bihar Military Police (BMP) jawans captured on Sunday," Avinash said.

He claimed that cadres provided first-aid to some of the BMP jawans who were critically wounded. The spokesperson denied reports that Maoists suffered more casualties in the encounter.

"Among those killed in the encounter were six Bihar Military Police personnel, Officer-in-Charge of Kawaiya police outpost Bhulan Yadav and a policeman," SP Ashok Kumar Singh said after reaching the spot.

Meanwhile, family members of abducted Abhay Yadav tried to meet Chief Minister Nitish Kumar to apprise him of the deadline set by the Maoists for freeing the policeman.

Relatives of Rupesh Kumar, the newly-appointed SI with first posting in Kajra, said that they had also received a call from Maoists.

Eyewitnesses claimed that the SP was heckled by BMP personnel who were upset after seeing the bodies of their colleagues killed in the encounter.

However, senior police officials including IG (Operation) K S Dwivedi and ADG (Headquarters) P K Thakur denied the reports.

Meanwhile, Chief Minister Nitish Kumar held a high-level meeting with top state officials to discuss the measures taken for ensuring the release of the kidnapped security men, officials said.

Bihar Home Secretary Aamir Subhani and DGP Neelmani also attended the meeting.