On Monday and Tuesday, it threatened detonate nine bombs in the district. On Tuesday, in a letter sent to the office of Assistant Commissioner, Land (AC land) Nayeb Ali, it threatened to kill the official.

In another letter sent to the Satkhira Press Club president on the same day, JMB also threatened that AC Land Nayeb Ali would be killed.

Bomb scare mounted in the district town yesterday after police arrested three JMB suspects from the bus stand. Law enforcers are on alert since the fresh threats, a senior police official told this correspondent.

Police have been deployed at key installations and paramilitary BDR is patrolling the town streets.

Entry of visitors have been restricted at the Collectorate Building, court premises, Police Superintendent's office and other important offices and installations.

Main gates of Judge Court building, Deputy Commissioner's office and Police Superintendent's office remain closed and visitors are allowed to enter only after checking their bodies with metal detectors and ascertaining their purpose of visit, sources said. The number of litigants in courts have also dropped.

Seeking anonymity, an intelligence official said, militants may now attack other installations as law enforcers have tightened security in court areas.

Some town dwellers talking to this correspondent said they are scared after the threats and arrest of the JMB suspects.

"This is affecting life and business", a trader said. "This is a new deadly menace which will paralyse everything", he said.

"I pull down the shutter before dusk and go home. I remain worried after sending my children to school", another shopkeeper said.

A senior leader in Satkhira district BNP declining to be named said he is worried about security after the threats. Bomb blasts can not be ruled out as Satkhira is a stronghold of JMB. They may retaliate, he said.

An Awami League leader said, bomb attacks are not unlikely as police failed to make any headway in nabbing members of JMB suicide squads though they are reportedly moving freely in certain areas.

Police Superintendent Abdur Rahim said, a drive to nab JMB suspects has been launched although they have gone into hiding. He hoped that police would be able to detect dens of militants and nab the kingpins.