The police were interrogating the arrestees until yesterday noon and will send them to jail custody today.

The arrestees are Chanchal alias Suman, 22, son of Jiban Mia, Md Siddique Mia, 38, son of Md Sadu Mia, Muhid Mia, 34, son of Dolon Mia, Md Rouf Mia, 25, son of Kulon Mia, Md Alamgir alias Joy Mia, 32, son of Kalu Mia, Jiban Mia, 28, son of Abdul Rouf, Md Sentu Mia, 25, son of Kalu Mia, and Mia Gias Uddin, 23, son of Dan Mia.

Brahmanbaria police have beefed up security in and around the Ahmadiyya-inhabited areas since the incident.

A team of police is still keeping close watch on the areas to maintain law and order. Officials from the Criminal Investigation Department (CID) and Special Branch (SB) of police have visited the spots.

The superintendent of police of the district, ATM Tareque, told The Daily Star different units of police are trying to trap the bomb attackers.

Officer-in-Charge (OC) Md Ismail of Kotwali Police Station said they have gathered much information about the Friday's attack. He however declined to reveal anything for the sake of investigation.

Three time bombs seized from East Kandipara and Bhadughar have been kept in water at the police station.

"We have sought army assistance for destroying the bombs," the OC said yesterday.