"The operation may start anytime, may be even tonight," said a Rab official yesterday evening, seeking anonymity. As part of the operation, the anticrime force will intensify their vigil in the border areas, he added.

Sources said Rab has taken the decision as killings and extortion are going on rampantly in Chuadanga, Meherpur, Jhenidah and Kushtia districts. The elite force has already set up camps at different places in these districts.

Some 61 people including BNP and Awami League activists, outlaws and other people have been killed since January this year in these districts. The increase in murders has created a sense of insecurity among people in the trouble-torn region.

Rab Director General MA Aziz Sarkar yesterday held a closed-door meeting with the superintendents of police (SPs) of the four districts at Chuadanga to discuss the operation.

Sources said the meeting discussed the latest positions of the outlawed groups, especially the four factions of Purba Banglar Communist Party (BPCP), which are more active than others. The SPs briefed the Rab DG on the extremists' activities in their districts.

The meeting also discussed the drive against Islamist militants in the four districts.

The SPs of Chuadanga and Meherpur were asked to intensify their drive against banned Islamist outfit Jama'atul Mujahideen Bangladesh (JMB) as police are yet to submit charge sheets in the cases filed for the August 17 serial blasts in the two districts.

A dozen of underground parties are carrying out extremism in the region and they have around 4,000 armed cadres, according to police.

In July 1999, a total of 2,492 cadres of various outlawed organisations surrendered under a general amnesty and deposited around 2,500 firearms to the police.

Of the parties, PBCP has four factions --- PBCP (Marxist-Leninist), PBCP (Janajuddha), PBCP (Communist War) and PBCP (Red Flag).

Tapan Malitha is leading the Janajuddha while Rony Biswas is the supremo of the Communist War faction. Rahul Raj is leading the Red Flag outfit. Sumon, who led the PBCP (M-L), was killed in "crossfire" in Khulna a few months back.

Chuadanga police announced Tk 1 lakh bounty on each of the 20 hardened outlaws on September 23 last year. Of them, Selim of Chuadanga was killed in "crossfire" last month while the rest are still evading arrest.