Former students of Rangpur Zilla School on Wednesday formed a human chain and held a mourning rally in Dhaka, demanding a fair investigation into the murder of a former teacher and four members of his family and exemplary punishment for those responsible.

The Rangpur Zilla School Ex-Students Club organised the programme in front of the National Press Club, with more than 100 former students taking part.

Around 11am, the participants held a mourning rally after marching along the road in front of the National Press Club and gathered near a police box, said a press release.

Agriculturist Abdul Bari, former additional secretary Shawkat Ali, Dr Arefin Amal Bagchi and Rakiquzzaman, all former students of the school, spoke at the rally.

The speakers said they were shocked by the killing of four members of the same family in Rangpur, describing it as an unprecedented incident in the city.

They said the murders had created fear and insecurity among residents and demanded that the actual perpetrators be identified through a proper and impartial investigation and brought to justice.

"No excuses will be accepted in the name of investigating the murders," the speakers said, warning that stricter programmes would be announced if their demands were not met.

They demanded the immediate arrest and exemplary punishment of those responsible for the deaths, including Ayush Chakraborty Priyam, who was a fifth-grade student of Rangpur Zilla School.

They also called for intervention from the highest level of the state to ensure justice for former teacher Ganapati Chakraborty and his family members.

Former students and teachers of the school said the killing of a teacher, his wife and their children in such a manner was unacceptable.

They said a swift and impartial investigation must uncover the circumstances surrounding the killings and ensure the maximum punishment for those responsible.