Bangladesh has arrested the prime suspect in the killing of a US blogger after authorities discovered threats posted on social media before the murder.

Authorities announced Monday that Farabi Shafiur Rahman was arrested while he was at a bus station in Dhaka, calling him the chief suspect for the crime that has sparked international outrage.

Avijit Roy, the American-Bangladeshi blogger who ran anti-extremism comments and articles on his blog was killed last Thursday by a man wielding machete in downtown Dhaka.

A spokesman for Bangladesh's elite Rapid Action Battalion (RAB) said Farabi had repeatedly threatened Roy in the social media

Major Maksudul Alam described Farabi as a “fundamentalist blogger” and the “main suspect,” behind the murder.

Authorities in the RAB said the suspect is a member of the outlawed Hizbut Tahrir.

The killing of Roy was met with heavy criticism inside Bangladesh, with some calling on the government to swiftly arrest and execute those behind such attacks. The United States also condemned the attack and pressured Dhaka to find the suspects as soon as possible.

US Federal Bureau of Investigation, FBI, has reportedly helped the Bangladeshi government in finding the suspect for Roy’s murder.

 MS/HMV/SS