Militant group Al Qaeda in the Indian Subcontinent (AQIS) has claimed responsibility for the murder of an American blogger Avijit Roy in Bangladesh as well as other "blasphemers" there and in Pakistan, according to SITE Intelligence Group in the US.

Roy, a prominent writer and secular activist, was hacked to death by two assailants with machetes on the streets of Dhaka in February as he returned from a book fair with his wife, PTI reported.

"Al-Qaeda in the Indian Subcontinent (AQIS) leader Asim Umar claimed credit for the murder of American citizen Avijit Roy in Bangladesh as well as other "blasphemers" there and in Pakistan, according to SITE, a US website that monitors extremist groups.

Umar's claim of responsibility for the deadly attack was reported to have been posted in a video posted on jihadist for a yesterday.

He also claimed the murders of other "blasphemers".

"Like the companions of the Prophet who defended him with their lives," Umar was quoted as having said in a statement that was released online yesterday, "The mujahideen of al-Qaeda have despatched to hell many who blasphemed against God, and insulted the Prophet."

The Bangladesh-born writer, who emigrated to Georgia some 15 years ago, was well known in his homeland for his Mukto-Mona (Free-mind) blog where he railed against all forms of organised religion.

He was also the author of a series of books, including the best-selling "The Virus of Faith", which triggered a controversy in Bangladesh.

Al-Qaeda leader Ayman Al-Zawahiri announced the creation of AQIS and introduced Asim Umar as its leader in a video posted online in September 2014.