The arrestees are JMB district commander Mohammed Abu Musa alias Enamul, 27, Mohammed Ajmat Ali, 28, his brother Mohammed Hasmat Ali, 35, and Mohammed Abdul Wahab, 40, according to a Rab press release issued at 9:30 last night.

The explosive materials recovered are 2,000 electric bomb detonators and 144 pieces of power gel, the release said.

Tipped off, a team of the crack crime-busting force netted Enamul, son of Mohammed Abdul Karim Akand of Char Laxmipur under Belkuchi upazila of Sirajganj district, at around 1:00am at Katakhali in the northwestern divisional city.

Enamul admitted to his involvement in the August 17 bomb blasts on the premises of the Court of Chief Metropolitan Magistrate, Rajshahi.

Acting on his confession, the Rab team arrested Ajmat Ali, son of Mohammed Nazir, at their Naodapara house in the city at around 4:00am. On information extracted from Ajmat, the law enforcers found Hasmat Ali hiding in the attic with 64 pieces of power gel.

The base of Asadullah al Galib, chief of another Islamist outfit Ahle Hadith Andolon Bangladesh (Ahab), is also located at Naodapara under Motihar Police Station.

The same Rab team then arrested Abdul Wahab, son of Mohammed Jasimuddin Sheikh, from their house at West Banshbari under Putia upazila of the district at around 5:30am.

Searching the house, Rab members recovered 500 electric detonators and 80 power gels from inside a computer casing hidden in a haystack. The team found 1,500 more electric detonators in a sound box hanging from the ceiling of the house.

The authorities concerned remained tight-lipped about the arrests and recoveries until issuing the press release at 9:30pm.

Sources said the detainees are being interrogated at the Rab-5 office and are coming up with information vital to national security.

Rab officials were too busy conducting one operation after another since the arrests to talk to the press. Despite repeated attempts, acting commanding officer of Rab-5 Major Salauddin could not be reached.

A highly placed law enforcement official, declining to give any details, just said, "We are keeping things secret for certain reasons. But, you [the media] will know everything later on."

He said, "The government has prohibited giving information to journalists about militants after it felt embarrassed by some newspaper reports and TV news interviewing militants."

An official order dated December 1 signed by AIG Abu Hasan Muhammad Tarik were distributed among all the Rab and police offices across the country early this month. The order was for the law enforcers not to provide journalists with any information about the arrested militants and not to let them take pictures or video footage of them without court orders.

Another source guessed that the fact that the recoveries were made in Galib's area might have something to do with the law enforcers keeping mum about it.

Elaborating on his theory, he said it is evident that an attempt is on to prove Galib not linked with militancy after State Minister for Home Affairs Lutfozzaman Babar remarked in September that Galib was not responsible for the August 17 countrywide blasts. The home ministry also sent lists of Galib's followers to police stations instructing not to harass them, the source said, adding Galib's associates even participated in an anti-militancy seminar with Babar in Dhaka on December 4.

However, he also accepted the possibility that the government might be keeping the matter secret in order to gather information about JMB linchpins and masterminds behind the attacks as well as their supply network of explosives.