A day after a nitrogen gas leak at a pharmaceutical factory in Maharashtra's Palghar district left four workers dead and two injured, police on Friday registered a case against the firm's four senior staffers, an official said, reported news agency PTI.

An official from the Boisar police station said that the case has been registered against the senior employees of the pharma company under Bharatiya Nyaya Sanhita (BNS) section 105, which concerns "culpable homicide not amounting to murder", reported PTI.

"They have been named in the FIR. The investigation is underway, and no arrests have been made so far," the official said, reported PTI.