Ziaur Rahman Shagor alias Sabbir, 27, one of the two JMB second-in-commands for Khulna division, was arrested in the city's Tootpara area at about 11:30pm on Thursday.

On his information, the Rab men busted the Jessore Students' Hostel at Daulatpur in the city and recovered three live bombs, 37kg potassium nitrate, 250gm gun powder, 100kg silver powder, three detonators, 18 integrated circuit boards, 16 capacitors, 60 resistors, 11 fuses, electric switches and eight pencil batteries, said a Rab press release.

The elite force recovered those from a room at the hostel that Sabbir, son of Gedu Molla of Shaikona village in Bagatipara upazila, Natore, had rented in guise of a puffed-rice vendor a week before August 17.

Director of Rab-6 in Khulna Lt Col Shams said around 2,000 bombs could be manufactured by the seized potassium nitrate. Sabbir and some other JMB men used to stay in the hostel where five-six students of Government BL College are now staying, he added.

The Rab release also said Sabbir has admitted that he gave the directives on the August 17 bomb attacks in Khulna, Bagerhat, Satkhira and Gopalganj, and distributed 34 bombs among the JMB cadres for the purpose.

Apart from Sabbir, also an ehsar of the banned Islamist militant outfit, the other second-in-command for JMB Khulna division is one Enam while one Hafez Mahmud is the commander. Rab sources said Sabbir has given the names of around 25 leaders and activists of different tiers of the outfit.

The repeated raids on JMB dens and arrest of some top leaders have disorganised their network, a Rab official quoted Sabbir as saying. The militant also told the interrogators that the top JMB leaders asked him not to contact them, who would rather contact him, if necessary.

Sabbir and the recovered items were handed over to Dautatpur police yesterday morning.

According to a Daulatpur police source, a group of JMB suicide bombers under Sabbir's command are staying in Khulna city under cover. They have the preparation to carry out bomb attacks at any available opportunity after receiving signal from Hafez, the source said.

Sabbir has given important information about the Islamist outfit's plan to implement in the southwestern region in January next year, the police said but did not elaborate on the matter on ground of investigation.

Meanwhile, the Rab and police have jointly launched a combing operation to arrest Hafez Mahmud and the suicide bombers.

The police believe that Sabbir also has links with the Purbo Banglar Communist Party Janajuddha and was involved in the November 19 bomb attack on policemen at Daulatpur and the November 20 attack at the Picture Palace cinema hall intersection.

The arrest of the JMB suicide bombers and other cadres is being given highest priority, keeping in view the New Year celebration on Saturday night, said a source in the Khulna Metropolitan Police intelligence.