Militants of banned Islamist outfit Jama'atul Mujahideen Bangladesh (JMB) have started regrouping in the remote villages of four upazilas in the district.
Police sources said JMB members who fled their localities during the crackdown after the August 17 serial bomb blasts in 2005 have returned to their areas in Shibganj, Bholahat, Gomostapur and Sadar upazilas and invited people secretly to join with them.
The JMB members collected arms from secret sources and trained up newly recruited members so that they can make arms and ammunition, police said.
Under this situation, police arrested four JMB members in Shibganj and Bholahat upazilas and recovered four locally-made guns and 14 rounds of bullet from their houses in last five days.
Police said many women also got involved with the outfit, as the JMB members have targeted women and youths for their membership.
Acting on a tip-off, a special police team from Dhaka arrested Abdul Munib, 25, from Koilardiar Sannayasi village Wednesday night and recovered a shooter gun and three bullets.
Earlier on June 14, police arrested Abdul Mumin, 24, from Khorogpur village under Shibganj upazila with a shooter gun and three rounds of bullet.
Following his confessional statement, police detained Abdul Rakib alias Sumon, 22, of Shamjola village in Shibganj upazila, and Rabiul Islam, 22, of Musribhuja Sonarpara village in Bholahat upazila, and found the firearms.
During the raids, police also seized books on jihad, three mobile phone sets and bullet-making materials.
Zannatul Hasan, superintendent of police of intelligence wing in Dhaka, said all the four arrestees admitted to their involvement with the outfit during interrogation.
"JMB members made only grenade and hand bomb in the past. But they are now making arms and ammunition at different places of the district. This is a new dimension and police realised it after the arrests of four JMB men Chapainawabganj," he added.
He said the JMB members are making bullets from the gun of spray insecticide machine. They also trained up the newly recruited JMB members so that the newcomers can make arms and ammunition.
The arrested JMB members have been working under the leaderships of Shahadat and Selim of Gomostapur upazila, police said according to the confessional statements of the detainees. The two men are mainly leading the regrouping of JMB.
Three JMB men were taken to four-day remand yesterday. Judicial magistrate court granted the remand for Abdul Rakib alias Sumon, Rabiul Islam and Abdul Munib. Another JMB member Abdul Mumin was also granted remand for four days.
Shibganj and Bholahat police filed separate cases against them under the Arms Act.