Bangladesh police on Sunday arrested a suspected Islamist militant from the border district of Ukhia, near camps where thousands of Rohingya Muslims fleeing a military crackdown in Myanmar have taken shelter.
The Rapid Action Battalion (RAB), an elite police tasked with tackling Islamist extremism in the Muslim-majority country, said it detained 30-year-old Sharful Awal for allegedly communicating with international Jihadist groups.
Awal was freed on bail in January after he was charged with anti-terrorism and explosives-related offences in the Chittagong region, RAB local chief Ruhul Amin said in a statement.
But after his release, Awal "communicated with various international militant groups through social media in an effort to establish Khilafat (a caliphate) through so-called Jihad," Amin said.
Police allege Awal is a member of a new faction of the Jamayetul Mujahideen Bangladesh (JMB), a homegrown Islamist group, and was involved in organising local extremists.
The new JMB faction has been blamed for a wave of attacks on foreigners and religious minorities, including the deadly attack on a posh Dhaka cafe last year in which 18 foreigners were shot and hacked to death.
But the RAB's Amin said authorities have not found any connections so far between Awal and Rohingya refugees.
An estimated 655,000 Rohingya have left Myanmar since late August to escape what UN officials have termed ethnic cleansing with possible "elements of genocide".
Most of the refugees have settled in Bangladesh's southeastern border areas like Ukhia.
Bangladeshi authorities have stepped up security and surveillance efforts in the Rohingya camps over fears the squalid settlements could be perfect recruitment grounds for homegrown and international extremist groups.
The country's border forces have also tightened patrols to prevent Rohingya militants -- who have carried out a series of attacks on Myanmar security posts since October last year -- from entering Bangladesh territory.