A gang armed with machetes hacked a secular blogger to death at his home in Dhaka this morning in the fourth such murder in Bangladesh since the start of the year, an activist group and police have said.

Niloy Chakrabarti, who used the pen-name Niloy Neel, was killed after the gang broke into his apartment, according to the Bangladesh Blogger and Activist Network which was alerted to the attack by a witness.

"They entered his room in the fifth floor and shoved his friend aside and then hacked him to death. He was a listed target of the Islamist militants," the network's head Imran H. Sarker told AFP.

Police confirmed Mr Chakrabarti had been murdered by a group of half a dozen people in the capital's Goran neighbourhood although they had no details on his background or the motive for the killing.

"There were six people who knocked his door, saying that they were looking to rent a flat. Two of them then took him to a room and then slaughtered him there," Muntashirul Islam, a deputy police commissioner, told AFP.

"His wife was in the flat but she was confined to another room."

Imran Sarker, head of a network of activists and bloggers said: "We are speechless. He was demanding justice for killing of other bloggers. Who will be next demanding justice for Niloy?"

Mr Chakrabarti is the fourth secular blogger to be killed in the Muslim-majority nation since February when Bangladeshi-born US citizen Avijit Roy, a writer and moderator of a blog site, was hacked to death in Dhaka.

The other victims include Ananta Bijoy Das who was attacked by a group wielding machetes on May 13 as he headed to work in Sylhet and 27-year-old Washiqur Rahman was hacked to death in Dhaka in March.

Bangladeshi authorities banned the hardline Islamist group Ansarullah Bangla Team (ABT) following Mr Das's murder in May, after facing accusations that they were doing too little to stop such attacks.

Bangladesh is officially secular, but more than 90% of its 160 million people are Muslim.