Among the arrestees, Bakul, 28, Azizul, 26, and Moktadur, 30, feature on the criminals' list of police who were put on high alert in the two districts after the incident. They are under interrogation by detectives.

The joint forces stepped up hunts for the operatives of the outlawed Purbo Banglar Communist Party (PBCP), blamed for the attack that came after BDR Lieutenant Abdullah Faruque led a raid on the farmhouse of Azizur Rahman in Jugnipasha village, 26 kilometres north of Khulna city.

Tuesday's fire by outlaws -- probably the first on the BDR personnel and the latest in a series of attacks on other law enforcers in Khulna since 2001 -- underlines security fears that led the government to launch an anticrime crack down codenamed Operation Spider Web in southwestern districts on July 19.

The joint forces launched combing operations in Abhoynagar, Phultala and Dumuria -- the upazilas believed to be strong bases of underground operatives.

Lieutenant Faruque, admitted to the Combined Military Hospital in Jessore with leg wounds he suffered in the firefight, will be operated on today.

Four policemen, including Officer-in-Charge of Phultala Police Station Ashraful Islam, were released from the local hospital Tuesday night after first-aid treatment for slight injuries.

Police said 32-year-old Shawkat Farazi who died in the half-an-hour armed confrontation with 50 rounds, was wanted in 12 murder cases.

Son of Babar Ali, Shawkat of Uttar Dingi village in Phultala is believed to have been linked to the PBCP, blamed for a long line of high-profile killings over the years.

Official records say the underground operatives carried out 25 armed and bomb attacks on law enforcers in the last 22 months, leaving 16 policemen dead and 28 injured.

The outlaws launched the first armed attack on police on January 26 in 2001 to snatch PBCP ringleader Abdur Rashid Malitha alias Tapan of Jhenidah from Khulna Judge's Court. Tapan is still at large.