Four students of a women’s madrasa were injured in a crude bomb blast in Kalkini upazila of Madaripur this morning, police said.

One of them was in critical condition and was sent to Dhaka Medical College Hospital for better treatment.

The incident occurred around 9:30am in a sitting room of Iman Sardar’s house, in front of Darussunnah Women’s Madrasa in the Gopalpur area of the upazila.

Farhia Rafiq Bhavna, additional superintendent of police (Crime, Sadar and Kalkini Circle) in Madaripur, confirmed the matter to The Daily Star.

She said the blast occurred in the sitting room, not inside the madrasa. The students had gone there to have their tiffin. They then spotted a ball-like object outside the sitting room and picked it up, triggering the explosion.

Police initially suspect that the object was a crude bomb.

Farhia said there had been incidents of crude bomb explosions and clashes in the area at different times over local dominance. However, it was not yet known how the bomb ended up there, and the matter was being investigated.

Members of the police, Criminal Investigation Department (CID) and Rapid Action Battalion (Rab) visited the scene following the incident, she said.

Locals rescued the four injured students after the blast and took them to Madaripur Sadar Hospital. Following initial treatment there, one student was sent to Dhaka for better treatment. The other three students are undergoing treatment at Madaripur Sadar Hospital.

Police said legal proceedings in connection with the incident are underway.