Police in a drive seized about 250 kilograms of bomb-making materials, crude bombs and chemicals from a madrassah in Keraniganj on Saturday, a day after a bomb blast left four people including a woman and two children injured there.

‘The operation is still ongoing. Crude bombs and bomb-making materials have been recovered. Detailed information will be shared after the conclusion of the raid,’ said Saiful Alam, officer-in-charge of Keraniganj police station,

Two women have been detained for questioning and a case will be filed, he said.

The Crime Scene Unit and Bomb Disposal Unit safely neutralised around 250 kilograms of bomb-making materials on Saturday afternoon, said the OC.

The explosion occurred on Friday noon at the building of Ummal Qura International Madrassah at Hasnabad, leaving madrassah director Sheikh Al Amin, 32, his wife Asiya Begum, 28, and their two sons—Umayet, 10, and Abdullah, 7, injured.

Asiya Begum and the two children were first taken to Ad-Din Hospital and later shifted to Dhaka Medical College Hospital.

Police said they heard the sound of an explosion from the madrassah in the afternoon.

Cracks were also developed in the roof and beams while two adjacent rooms and a neighboring building sustained partial damage after the explosion.

Afser Uddin, a local resident, said around 50 students used to study at the madrassah but it was closed on Friday due to weekly holiday.

According to local people, three rooms on one side of the building were used for madrassah activities while Al Amin had been living with his family in another room on the opposite side for the past three years.

Humayun Kabir, a resident of the adjacent building, said parts of their building were damaged.

‘I was returning home after parking my car when the explosion occurred. Bricks fell on my head and I lost consciousness. Locals took me to a hospital,’ he said.

Parveen Begum, the house owner, said Mufti Harun had been running the madrassah in her building for three years and later handed over its management to his brother-in-law Al Amin and his wife.

‘I used to keep in touch regularly but I had no idea what was happening in the guise of a madrassah,’ she said.