Kolkata: Putting an official stamp on 'Operation Green hunt', a joint anti-Maoist operation to be launched by four affected states, Union Home Minister P Chidambaram today asked the ultras to shun violence or face the armed campaign.

'' We are making appeal again to Maoists to abjure violence, halt violence. Otherwise they will have to face armed onslaught, '' he told newsmen after approving the ''Operation Greenhunt'' at a high level meeting with the Chief Ministers of West Bengal and Orissa and high officials of Bihar and Jharkhand at the state secretariat.

Mr Chidambaram regretted that the earlier appeal to Maoists to stop violence did not yield any result forcing the Centre for the continuance of the joint force's operation.

The Minister, however, said the Centre was not averse to discussion with Maoists provided they ''halted'' violence.

'' We have reviewed the intra-state and inter-state operations against Maoists and the latter will be carried on among West Bengal, Bihar, Jharkhand and Orissa, '' Mr Chidambaram observed.

He asserted that the joint forces, carrying out operation in the trouble Jangal mahal of West Bengal stretching over three districts, would 'reclaim' within six months the areas being controlled by the underground Maoists. The joint forces had already made ''significant progress'' by nabbing a number of key Maoist leaders, Mr.Chidambaram added.

'' Our target is not to kill anyone but to re-establish civil administration in the Maoist-dominated places and start the developmental works, '' he maintained.

Rejecting the accusation of ''non-performance'' against the joint forces, Mr Chidamram said, '' We are continuing a careful, calibrated and controlled operation which is making slow but steady progress. ''

Besides Chief Minister Buddhadeb Bhattacharjee and the senior government officials, the meeting was attended by Orissa Chief Minister Naveen Pattnaik, Jharkhand Deputy Chief Ministers Raghubar Das and Sudesh Mahato, Bihar Home Secretary Amir Suhani and DG Ananad Shankar.