All the nine are on a five-day remand. The four made confessions before a First Class Magistrate under Section 164, police sources said.

They are 'divisional commander' Abdur Rashid Asif, 'commander' Faruk Hossen Amzad, and suicide squad members (ehsars) Md Rabiul Islam alias Kamal and Ehsanul Haq Mesbah.

Detective Branch police have shown the four militants arrested in the case filed earlier in connection with the August 17 blasts.

Police sources said all the nine are being interrogated.

During their arrest, Rab (Rapid Action Battalion) also recovered a huge quantity of bomb-making materials from their rented house in Kazi Para, Rab officials told newsmen on Tuesday.

Two cases have been filed, one under the Explosives Act and the other under the Arms Act in this connection with Saidpur thana, police said yesterday.

Meanwhile a controversy has arisen as to when the militants were arrested.

Some sources claimed that unknown and suspicious people used to visit the militants' rented house at Kazi Para.

House owner Abdul Gani Mridha on Tuesday morning in presence of Rab and police admitted before newsmen that Rab-10 members arrested six people including his tenant Abdur Rashid Asif while they were holding a meeting at his house.

He (Abdul Gani) also said that the Rab members recovered explosives and other bomb-making materials from his tenants' house.

But after departure of Rab men, he (Abdul Gani) told newsmen that on Monday midnight, some Rab members came to his house and gave him a piece of paper with some writings. "They (Rab) asked me to give statement as per the writings on the paper before any visitor. I did so out of fear", he added.

Some people raised the question why the house owner was not arrested after recovery of explosives from his house.

Rezia Aktar, mother of Faruk Hossen alias Amzad of Titpara village in Dimla upazila, told newsmen yesterday and the day before that Rab arrested his son, their neighbour Rabiul Islam and Kamal on January 30.

The news of their arrest was published in different daily newspapers on January 31 and February 1.

"But now I am surprised to hear that my son Amzad arrested from Saidpur Monday night (February 6)", Rezia Aktar said.

Some police sources on condition of anonymity also told newsmen that Wahidul Islam Sayem, 'Nilphamari district commander' of JMB, hailing from Ranisonkail in Thakurgaon, was arrested about a week ago.

Abu Bakar Siddiq alias Nahid, JMB's Kurigram 'district commander' and suicide squad member Ehsam Haq were also arrested a week ago, the police sources claimed.

When contacted, Maj. Ershadul Hoq who led the Rab operation told newsmen yesterday that all the JMB men were arrested Monday night.