Detectives yesterday filed charges against eight members of banned militant outfit Ansar Al Islam, also known as Ansarullah Bangla Team (ABT), in connection with the murder of publisher Faisal Arefin Dipan in October 2015.

Assistant Commissioner of Detective Branch (DB) Fazlur Rahman, also investigating officer of the case, submitted the charge sheet to the Chief Metropolitan Magistrate's Court of Dhaka, showing 26 people as prosecution witnesses.

Six of the eight suspects have been arrested under several cases, including the one for the murder of Dipan. They have also given confessional statements before magistrates on different dates, admitting their involvement in the killing, claimed police.

The six arrestees are killing squad leader Moinul Hasan Shamim alias Samir alias Imran, 24; trainer Abdus Sabur alias Samad alias Sujon alias Raju, 23; and top ABT operatives Khairul Islam alias Fahim alias Jishan, 24; Sheikh Abdullah, 27; Abu Siddiq Sohel, 34; and Mozammel Hossain alias Saimon, 25.

Apart from them, police claimed that sacked army major Syed Ziaul Haq, the military wing commander of the outfit, planned the killing. Zia and another suspect Akram Hossein alias Hasib are still on the run.

The charge sheet will be placed before the court on December 18.

Faisal Arefin Dipan, 43, was the publisher of Jagriti Prokashani. He was hacked to death at his office in Dhaka's Shahbagh on October 31, 2015. Later, his wife filed the case with Shahbagh Police Station accusing unknown persons.

Dipan was stabbed twice in the head and once in the neck with a machete, according to the autopsy report.

Just hours before the attack, publisher Ahmedur Rashid Tutul and his friends, bloggers Ranadipam Basu and Tareque Rahim, were injured in a machete attack at Tutul's publishing house Shuddhoswar in Lalmatia.

Both Tutul and Dipan were publishers of writer-blogger Avijit Roy, who was hacked to death by assailants in TSC area of Dhaka University on February 26, 2015.