Six persons were injured after an explosion took place inside a scrap metal factory at Malipanhghora in Howrah on Wednesday morning.
Four labourers are critical and have been admitted to Howrah District Hospital.
According to police, the explosion took place around 8 am inside factory premises in the Ghusuri area of Malipanchgora.
Two labourers were cutting a cylinder using a gas cutter and as soon as the cylinder was cut, it exploded. Due to the impact, two labourers suffered critical injuries on the lower portions of their bodies.
Four other labourers who were working nearby also suffered injuries from the metal particles that spread all over the area due to
the explosion.
Later police and the fire brigade rushed to the spot. Firefighters conducted an inquiry to ensure that there is no gas leakage. Police said that a case will be initiated once the fire brigade authority lodges a complaint against the factory owner.
Local people alleged that illegal work is being carried out at several factories inside the same premises everyday. Earlier, such incidents had taken place more than once but no action was taken against factory owners.
Meanwhile, on Wednesday, a three-member forensic team visited the site in Maheshtala where an explosion had taken place a few days ago.
Samples have been collected for examination to determine the nature of the explosive that was used.