DHAKA, Bangladesh (AP) — Police in Bangladesh said Sunday that they have arrested a suspected Muslim militant for his alleged involvement in the killing last month of a gay rights activist and his friend in the capital.

Police identified the suspect as Shariful Islam Shihab, a former member of the banned Islamic group Harkatul Jihad. They said he joined another militant group, Ansarullah Bangla Team, in mid-2015.

Shihab, 37, was arrested in the southwestern district of Kushtia, Munirul Islam, head of a newly formed police counterterrorism unit, told a news conference. He did not give any further details.

There have been a series of recent attacks targeting atheists, moderates and foreigners in Bangladesh. Only one of 15 such killings has been prosecuted since 2013.

Islam said that Shihab allegedly killed Xulhaz Mannan, who worked for the U.S. Agency for International Development, because he was a gay rights activist and promoted the gay community's cause through a magazine as an editor.

He said Shihab told police during questioning that he took part in stabbing to death Mannan and his friend as ordered by his group's high command. There was no independent confirmation of the police officer's claim.

Police earlier said they identified at least five people who took part in the killings on April 25 from video footage collected from buildings near the crime scene in Dhaka's Kalabagan area.

"We are checking the footage to determine whether Shihab is visible there," Islam said.

The Bangladeshi branch of al-Qaida had claimed responsibility for the April 25 killing of Mannan and his friend, Tanay Majumder. Mannan was also a cousin of former Foreign Minister Dipu Moni of the governing Awami League party.