After conducting a raid at different places, police arrested the factory manager Atanu Saha and two of its directors - Pranab Kumar Kar and Prabhat Kumar.
They were remanded in police custody after being produced before a court on Monday. Police have booked them under sections 284 and 287 of the Indian Penal Code.
It may be mentioned that around 35 workers including four children fell ill after inhaling ammonia gas which leaked from the air-conditioning plant of a prawn processing unit in Buderhat area of Panchasayar in the southern fringes of the city on Saturday night.
Senior police officers and disaster management team rushed to the spot following the incident and admitted the injured workers in nearby hospitals. Some of the victims were stated to be in serious condition.
Local residents felt a foul smell originating from the AC plant of the prawn processing unit near Upahar complex on Saturday night. The workers started feeling a burning sensation in their eyes and felt their throats getting choked. Those who fell ill were soon removed from the place.
Police and disaster management teams managed to spot the source of the leakage which was inside the AC plant of the factory.
Four fire tenders were pressed into the action. The police had evacuated the unit and all the workers were brought out.
The members of the disaster management team identified the gas as ammonia. A technical team and engineers were soon swung into action who visited the spot and started the repair work. They repaired the portion of the AC plant that had developed a crack.
After investigating the incident, the police and fire departments found some security lapses in the factory. They found that the firefighting measures for the factory were not properly taken.
They were also looking into whether the unit authorities were running the factory with all the necessary licenses from the fire department.