He worked closely with the group’s fugitive military chief Syed Mohammad Ziaul Haque, an expelled army major, the police’s counter-terrorism chief Monirul Islam said at a media briefing on Tuesday.
A court ordered him to be remanded in police custody for five days.
Ashfaqur, arrested from Bhatara on Monday night, had come to Dhaka from Sylhet to meet another operative from the organisation, he said. “We arrested him based on a tip-off.”
Ansarullah Bangla Team or the ABT came to be known after the fatal machete attack on blogger and Ganajagaran Mancha activist Rajib Haider in 2013. Its chief Mufti Jasimuddin Rahmani is in prison after his conviction in the murder.
The extremist group banned in 2015 has been linked to the murders of more secular writers, including Avijit Roy. ABT changed its name to Ansar-al Islam Bangladesh, police said. The murders were also blamed on a revived section of the Jama’atul Islam Mujahideen or Neo-JMB.
A failed coup in 2012 brought forward the names of former army major Ziaul Haque and expatriate businessman Ishraq Ahmed.
Zia’s name resurfaced amid a series of assassinations of bloggers, online activists, authors, publishers, foreign nationals and people from religious minority groups that took place during the last two years.
After last year’s Gulshan attack, the government expanded its crackdown on militants. Neo-JMB’s chief Tamim Chowdhury died in a police raid, but Zia continued to elude law enforcers.
Ashfaqur has admitted to meeting Zia outside Dhaka few months ago, said Monirul.
Police will try to gather details on the militants’ next plan when Ashfaqur is questioned in remand, he said.
Ashfaqur, a student of computer science at Shahjalal University of Science and Technology, took military training after joining the group two years ago, said the counter-terror chief.