Bangladesh's anti-terrorism unit said it had arrested on Monday the main suspect in the killing of a US blogger Avjit Roy who was hacked to death in Dhaka last week in the latest attack on critics of religious extremism in the Muslim-majority nation.Forces from the Rapid Action Battalion (RAB) arrested Farabi Shafiur Rahman, who was previously jailed for his ties to the extremist Hizbut Tahrir Islamist group, at a bus stop in Dhaka, a RAB spokesman told reporters.

The spokesman said Farabi had confessed to threatening to kill blogger Avijit Roy. Farabi was still being interrogated.