Law enforcers have been able to identify three alleged killers including the mastermind in connection with the murder of LGBT rights activist Xulhaz Mannan and his friend Mahbub Tonoy.

The killers were well trained and they had planned the killing two months ago, Monirul Islam, chief of counterterrorism unit of Dhaka Metropolitan Police (DMP), told journalists at a press conference at DMP media centre today.

Last night, law enforcers arrested a man named Shariful Islam alias Shihab, 37, at Chhoy Rasta intersection in Kushtia Sadar upazila in connection with the murder.

He was produced before the court of Additional Chief Metropolitan Magistrate Kaisarul Islam, which placed him on three-day remand this afternoon. Detectives sought a ten-day remand for him.

Shariful is an active member of the banned militant outfit Ansarullah Bangla Team, Monirul said at the conference.

READ more: 2 hacked to death in Dhaka flat

In a primary interrogation, Shihab confessed that he had been a member of another banned Islamist outfit Harkat-ul Jihad al Islami, Bangladesh (Huji) before he joined Ansarullah Bangla Team, he added.

Law enforcers seized four mobile phone sets, a tab and a USB flash drive from his possession, Monirul Islam said.

Also Read: Ansar Al Islam claims responsibility

The detainee also admitted that he supplied one of the two firearms found at the killing site, the police official said.

It has been suspected that Shariful might have been in the backup team of the killers, Monirul Islam said at the briefing.

On April 25, unidentified assailants hacked to death Xulhaz and Tonoy at a flat in the capital's Kalabagan area.

Xulhaz, 42, was a Political Process Analyst at the USAID. He was also an editor of “Roopbaan,” the country's only known magazine for the LGBT (lesbian, gay, bisexual and transgender) community.

Ansar Al Islam or Bangladesh branch of al-Qaeda in the Indian Subcontinent (AQIS) has claimed responsibility for the killings, according to US-based monitoring agency SITE Intelligence Group.