Joint forces including army, Rapid Action Battalion (Rab), police and other law enforcing agencies searched the whole court compound and all rooms and clamped a two-stage security blanket in the area.

Every body entering the compound was thoroughly searched with metal detectors at the gate, courtroom entrances and at other points.

Judges, lawyers, clerks, clients, witnesses, visitors, court officials and other staff were allowed entry after physical search.

People without any appointment or work in court were not allowed to enter and so the usual rush and gathering of crowds were not seen. All courts functioned normally.

District Judge Md. Safiuddin and Judge Mainuddin declined to make any comment about this. Law enforcement agencies were informed of the letter and they will decide the action, the two judges said.

Sunday morning, sweepers while cleaning some rooms found similar hand-written letters signed by one Sanaullah Hugli, identifying himself as a member of Al-queda.

The letters in Bangla addressed to Second Additional District and Sessions Judge Md. Mainuddin Islam said he was cautioned many times earlier to abstain from dutiers and is now being asked for the last time to stay away from court.

"Otherwise, no one but Allah knows what will happen", it said.