A 28-year-old Bangladeshi law student who was critical of radical Islamists has been hacked to death here by machete-wielding militants, the latest in a series of attacks on secular bloggers and activists in the Muslim majority country.

Nazimuddin Samad, a masters student of the state-run Jagannath University's law department, was killed by suspected Islamist militants in Old Dhaka's Sutrapur area last night. He was attacked by three assailants while walking to his home in Gendaria with another youth after completing classes at the university near Bahadur Shah Park.

While murdering Samad, the killers shouted Allahu Akbar (God is Greatest), witnesses said.The youth accompanying the victim has been missing since the incident, a police official said.

"They initially hacked him and then fired gunshots to confirm his death," the official said. Nazim, who hailed from Sylhet, was the information and research secretary of Sylhet district unit of Bangabandhu Jatiya Jubo Parishad. He was also an activist of Gonojagoron Moncho's Sylhet wing.

His friends said Nazim used to campaign for secularism on Facebook and was critical of radical Islamists. A day before the murder, he expressed concerns over the country's law and order in a Facebook post.Businessmen in the area closed their shops immediately after hearing the gunshots. Police cordoned off the crime scene. They recovered a bullet shell from the spot.

Nurul Amin, assistant commissioner of Sutrapur division, was quoted as saying that police went to the spot and found the body in a pool of blood. Nurul said it was clear that the assailants kept an eye on Nazim's activities for long. University Proctor Nur Mohammad said Nazim got admitted to the university two months ago.

"We have informed his family about the murder and are taking detailed information about him," he said. There have been systematic assaults in Bangladesh over the past six months specially targeting minorities, secular bloggers and foreigners. Last month, a 65-year-old Christian convert was hacked to death in the northern Bangladeshi town of Kurigram by three motorbike-borne unidentified assailants.Last year, Bangladesh-born US blogger and science writer Avijit Roy, 42, was attacked just yards away from a book fair in Dhaka. A month later, fellow blogger Washiqur Rahman, 27, was hacked to death in broad daylight near his home in Dhaka's Tejgaon area.

The subsequent victims were Ananta Bijoy Das, 33, a banker and a founder of a group called the Science and Rationalist Council; Niloy Chakrabarti, 40, who wrote online under the pen name Niloy Neel and publisher Faisal Arefin Dipan, 43, who published a bestselling book by Roy. The Islamic State has claimed a series of attacks in the Sunni-majority Bangladesh.