Lalgarh (West Bengal), Aug 6 - The security operation carried out by the police and paramilitary forces to flush out Maoists from the trouble-torn belt of Lalgarh has not received satisfactory results, the West Bengal government conceded Thursday.

'Initially, we received significant success in establishing the rule of the law in Lalgarh, but in the latter half of the operation the result has not been very satisfactory,' Home Secretary Ardhendu Sen told reporters after a meeting with senior state police officer.

'As a matter of fact, we have seen that the incidents of killing and abduction are taking place there. We've also not been able to arrest those top-rung Maoist leaders who have taken shelter in the inhospitable forest terrains of Lalgarh.

'As the central paramilitary forces would not stay in Lalgarh permanently, we'll have to plan for a time-bound operation, say for next 15-25 days, to improve the law and order situation in the region,' Sen said.

Condemning the growing Maoist activities in Lalgarh, the state's ruling Left Front (LF) chairman Biman Bose said the joint operation was still on in that belt.