Bangladesh police have arrested a suspect over the murder of two gay-rights activists, part of a series of murders of intellectuals, writers and religious minorities.

The arrest of Shariful Islam Shihab, in the southwestern Kushtia district on Monday, came three weeks after six attackers carrying machetes and guns killed Xulhaz Mannan, editor of a magazine for Bangladesh's lesbian, gay and transgender communities, and fellow activist Mahbub Tonoy in a Dhaka apartment last month.

Why all of these sudden killings in Bangladesh?

"We've arrested one man in connection with the murder of Xulhaz Mannan," Maruf Hossain Sorder, Dhaka police spokesman, told AFP news agency.

"He is a member of the Ansarullah Bangla Team."

Police said Shihab - who has denied carrying out the killings - owned one of two guns that were used in the murders.

The Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group has claimed a number of the killings, but authorities insist there is no evidence of the group's presence in the country, saying homegrown groups are behind the attacks.

Blame game

An al-Qaeda-affiliated group said that it was behind the killings of Mannan and Tonoy, saying the two men had worked to "promote homosexuality" in Bangladesh.

Bangladesh police chiefs have said that their murders bear the hallmarks of local armed groups, while the secular Awami League-led government of Sheikh Hasina, the prime minister, has blamed the opposition.

"The government cannot guarantee that the attackers are not sheltered by elements of the ruling party," Abbas Faiz, a human-rights and South Asia researcher, told Al Jazeera from London.

"They are the only government in Bangladesh's history that has intensely politicised human rights.

"If anyone touches [the government] on these issues, they find themselves in trouble ... They are presented as being connected to [the opposition] Jamaat-e-Islami [party]."

Sunday's arrest came a day after an elderly Buddhist monk was found hacked to death in a temple in the southeastern district of Bandarban - the seventh such killing since the start of last month.

Last year four secular bloggers and a publisher were hacked to death. Christians, Hindus and Sufi, Ahmadi and Shia Muslims have also been killed since.

No one has yet been convicted over those deaths, despite a number of arrests.

Source: Al Jazeera and agencies