Police arrested the alleged killer Azizul Haque, a businessman, soon after the incident.

Police and locals said Azizul alias Bachchu, 26, son of Hafiz Uddin of Pithua village in Kishoreganj, was living at a rented house in Jolonda for the last four years.

He often used to tease Pakhi Begum, 13, daughter of Nurul Islam Chandu, and also proposed to marry her. But his proposal was turned down.

Police said Bachchu killed Pakhi, a student of class six, and her sister Sumaiya Begum, 2, with a sharp weapon when their parents were not home.

They added that neighbours rushed to the scene, hearing groans of the sisters, and caught Bachchu with the weapon at his hand. They handed him over to police.