Dhaka: A Dhaka court on Saturday placed alleged militant leader Arafat Rahman Siyam alias Sajjad, who was arrested on Friday night over the killing of blogger and writer Avijit Roy, on a five-day police custody for interrogation.

Dhaka Metropolitan Police had earlier announced a Tk 2 lakh bounty for information leading to the arrest of Arafat.

A team of Counter-Terrorism and Transnational Crime (CTTC) unit of DMP with the help of Detective Branch of Dhaka district police conducted a drive at Baradeshi of Aminbazar in Savar at about 7:00pm and arrested Arafat, who was a member of the operational team of banned Islamic outfit Ansarullah Bangla Team (ABT), said Masudur Rahman, DMP Deputy Commissioner (Media), Saturday.

Arafat was produced before the Metropolitan Magistrate court in the afternoon seeking remand for interrogation. After hearing, the court granted a 5-day remand, he said.

Masudur claimed that soon after his arrest, Arafat confessed to his involvement in the several sensational murders, including that of Avijit, former USAID staff Xulhaz Mannan, blogger Niladri Chattopadhyay Niloy and publisher Faisal Arefin Dipon.

He also revealed that the mastermind of Avijit assassination was Mukul Rana alias Sharif who led a five-member team comprising himself in the killing mission.

They swooped on Avijit and his wife at the Teacher-Student Centre (TSC) on the Dhaka University campus on February 26 in 2015 during the Amar Ekushey Book Fair and hacked them with sharp weapons, the DMP official said.

Avijit Roy, a Bangladesh-born US citizen and founder of Mukto-Mona blog, was hacked to death and his wife Rafida Afrin Banya was injured as unidentified miscreants attacked them with meat cleavers.

Avijit succumbed to his injuries at Dhaka Medical College Hospital soon after he was taken there.

The CTTC has so far arrested 11 people in connection with the Avijit murder. Two of them have reportedly already given confessional statements before court.

Xulhaz Mannan and his friend Mahbub Tanoy, an activist of theatre group Loknatya Dal, were hacked to death by some unidentified miscreants at an apartment in the capital's Kalabagan area on April 25, 2015.

On August 7 in 2015, blogger Niloy, a resident of a rented flat on the 4th floor of a multi-storey building at Goran in the capital, was hacked to death by a group of assailants.

Faisal Arefin Depon was also hacked to death at Aziz Super Market at Shahbagh on October 31 in 2015.