The toll in the blast at an illegal firecracker factory in West Bengal's North 24 Parganas district rose to nine with one more body recovered from a pond, a senior police officer said on Monday.

One person was arrested in connection with the blast, the officer said.

The situation at Nilgunj's Moshpole within Duttapukur police station limits was calm on Monday.

The headless body was recovered from a pond while the head was found from the courtyard of a neighbouring house, the officer said, adding that one hand and two fingers were also found in the surrounding areas of the explosion site.

Police continued their investigation the entire night and arrested one person, whom they suspect is the partner of the owner of the illegal firecracker factory, he said.

The man has been booked under the Explosives Act 1884 and Explosives Rules 2008, the officer said, adding that a suo moto case was started against three others in connection with the blast, he added.

"The search operations continued the entire night. However, the lack of power in the area and the huge amount of debris scattered made it tough for us to conduct the searches and our investigation. We have arrested one person who was the business partner of the man running the unit," the senior police officer of Barasat Police District told PTI over the phone.

The explosion in the illegal firecracker factory in North 24 Parganas district took place at around 8:30 AM on Sunday when people were working in the factory.

The blast's impact was so intense that over 50 houses in the neighbourhood were partially damaged and body parts of people were found on terraces of several buildings.

Police said the owner of the illegal firecrackers factory and his son, who was present in the unit, were also killed in the blast.

Police and local administration employed JCB machines to bring down the remaining part of the building, housing the illegal firecracker unit and clear debris from the area, the officer said.

Talking about the condition of those injured in the blast undergoing treatment at the Barasat Medical College and Hospital, the police officer said that the condition of one remained "very critical" while others were improving.

Many local people alleged that despite complaining to the police regarding the illegal firecracking unit, no action was taken.

"Now, when so many lives have been lost, what will the police do in arresting people? They should have taken necessary actions when we had complained to them," Ratan Hasan Ali, a local, said.

Twelve people were killed in a similar explosion at an illegal firecracker factory in Purba Medinipur district's Egra in May while three died in another explosion in Maheshtala in South 24 Parganas district.

Soon after the blast, the TMC and BJP engaged in a war of words with the saffron party demanding a NIA probe while the Trinamool asked the BJP to stop doing "vulture politics."

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