Another Christian has been hacked to death by Islamist militants in Bangladesh.

Sunil Gomes was attacked at his grocery store after the morning service in his home in the village of Bonpara. The attackers have not been identified or apprehended but Islamic State claimed responsibility for the killing.

Father Bikash Hubert Rebeiro, from the Bonpara Catholic church, told AFP that Gomes, whose brother is a priest, used to work as a gardener at the church and was "known for his humility".

"He attended Sunday prayers at my church and then went to his grocery store. The next thing we know he was hacked to death. I can't imagine how anyone can kill such an innocent man," Rebeiro said.

Gomes was murdered only hours after the wife of a successful anti-terror official was killed in front of her young son.

Mahmuda Aktar was taking her son to board the bus to school near her home in the southeastern city of Chittagong when three men on a motorcyle stabbed and shot her. Her husband Babul Aktar has played a key role in cracking down on militants in the region and it is believed she may have been targeted in retaliation.

As many as 40 people have been killed during the last three years by Islamist extremists, either members of religious minorities or secularist activists. While responsibility for the killings has been claimed by Islamic State and Al-Qaeda, the government has denied that either group is active in the country, blaming home-grown extremists instead.