Police today claimed to have arrested an alleged militant accused in blogger and writer Avijit Roy murder case.

Accused Arafat Rahman alias Siam alias Sazzad, 24, is a member (operation branch) of the banned militant outfit Ansar Al Islam, Masudur Rahman, deputy commissioner (media) of Dhaka Metropolitan Police (DMP), told The Daily Star.

Acting on a tip-off, a team of Counter-Terrorism and Transnational Crime (CTTC) unit of DMP along with Detective Branch (DB) of police of Dhaka district arrested Arafat from Amin Bazar-Bardeshi area in Savar upazila last night while he was trying to meet his accomplices, the police official said.

Earlier, DMP had declared bounties on him and five others, he added.

With this arrest, 11 accused were so far arrested in the sensational murder case.

Two of them earlier gave confessional statements before the courts.

In a primary interrogation, Arafat confessed to the law enforcers that four members of the militant group, led by Mukul Rana alias Sharif, made the attack on blogger Avijit Roy and his wife Rafida Ahmed Bonya on Dhaka University campus on February 26, 2015, Masudur Rahman said.

The attack was carried out following the instruction of sacked and absconding army Major Syed Ziaul Haque, the alleged military wing chief of the banned militant outfit, the police official also said.

Arafat also admitted his involvement in the killings of blogger Niladri Chattopadhyay Niloy on August 7, 2015 in Khilgaon, LGBT rights activists Xulhaz Mannan and his friend Mahbub Rabby Tonoy on April 25, 2016 in Kalabagan, and publisher Faisal Arefin Dipan on October 31, 2015 in Shahbagh, police claimed.

Dipan, the owner of Jagriti Prokashony, published several books written by Avijit. 

A Dhaka court later placed Arafat on a five-day remand after police produced him before it seeking 10-day remand to interrogate him.

Police said they will later appeal to the court to show him arrested in other killings.

Avijit, a Bangladesh-born US citizen, was hacked to death on DU campus when he along with his wife Rafida Ahmed Bonya was returning from the book fair that day in 2015. Bonya was critically injured in the attack.

He came to Bangladesh with his wife as his two books were published during that year's book fair.