At least three of the four militant suspects arrested in Sunday's raid on an Ashulia den were out of touch with their families for months.

The leaders of “Sarwar-Tamim group” of Jama'atul Mujahideen Bangladesh (JMB) told them to do so, said a Rab official quoting the arrestees.

Irfanul Islam of Chittagong's Raozan upazila went traceless after he left home on May 2 to go to a coaching centre in Chittagong city, his uncle Azam Khan told The Daily Star.

As his family failed to reach him on his phone, they lodged a general diary with Hathazari Police Station the next day.

“We did not notice anything suspicious about Irfan, who passed HSC from Chattagram Biggan College last year,” said Azam.

Another arrestee Mozammel Haque alias Masud, 18, who studied in a Qawmi Madrasa, came to Dhaka from Shankivanga village in Mymensingh around a year ago and started working at a mosque as Imam.

“He stopped being in touch with us seven or eight months ago,” his elder brother Tofail Ahmed said.

The family, however, said they didn't know whether he was picked up by someone.

The four suspects were produced in a Dhaka court yesterday in a case filed by Rab with Savar Police Station on April 28. The Court placed each on a four-day remand.

Rab filed two more cases with Ashulia Police Station against the four young men.

The suspects surrendered to Rab officers on Sunday, about 12 hours after Rab personnel cordoned off a tin-shed house in Ashulia.

The third arrestee Rashedun Nabi Rashed, 22, of Gaibandha's Fulchori upazila, left his mess in Bogra's Sutrapur with two unknown persons on May 1, said his brother-in-law Nazmul Rahman.

Rashed was a student of SAIC Institute of Medical Technology in Bogra. His brother Raihan Islam filed a general diary with Bogra Sadar Police Station on May 28.

On the other hand Alamgir Hossen, 18, of Sunamganj's Jamalganj upazila, was the eldest of three siblings. He dropped out of Madrasa after class-VII and started working in a spinning mill in Dhaka.

“My son came home in March. About one and a half month ago, I got his last phone call. I asked him to give me Tk 500. He sent the money but didn't call me after that,” his father Abdul Hannan said.

Rab-4 Commanding Officer Khandker Lutful Kabir said they will interrogate the men to find out how they gathered in the Ashulia den from different districts.

Our correspondents in Mymensingh, Savar, Gaibandha, Moulvibazar contributed to this report