Japanese citizen Kunio Hoshi, who was gunned down in northern Bangladesh district of Rangpur on October 3, was buried at a local graveyard early today as per Muslim burial rituals.

Hoshi, 66, was laid to rest at Munshipara graveyard in Rangpur city at 4:05am today, Additional District Magistrate (ADM) Priyosindhu Talukder told The Daily Star.

He was buried at the local graveyard as per the instruction "from the higher authorities", Talukder said, without detailing further.

According to Sharfuddin Ahmed, mayor of Rangpur City Corporation, Hoshi converted to Islam. "From the documents we have in our hands, he became a Muslim," Ahmed told The Daily Star.

The representatives from both Bangladesh and Japanese governments attended the prayers before burial on the premises of Rangpur Medical College Hospital.

Motorbike-riding gunmen shot dead Hoshi, 66, near his agriculture project in Kaunia Upazila (sub-district) of Rangpur district on October 3.

Investigators arrested two and detained six people including Hoshi's friends in the locality and questioned several ones but failed to find any clue to the killing yet.

After the killing – which came just five days after Italian national Cesare Tavella, 50, was shot down in high-security diplomatic zone of the capital – Reuters reported that international terrorist organisation Islamic State claimed responsibility of the murder.

IS had also claimed responsibility of Tavella's murder.