The tank from which liquid oxygen leaked at a civic-run hospital in Nashik, killing 24 Covid-19 patients, was operationalised just 21 days before the incident, an official said on Thursday.

The incident occurred on Wednesday afternoon when the patients, who were either on ventilator or oxygen support, suffocated to death after their oxygen supply stopped suddenly because of a malfunction in the main storage at Dr Zakir Hussain Hospital in Maharashtra's Nashik city.

The police registered an FIR on Thursday against unidentified persons under Indian Penal Code Section 304-A (causing death by negligence) following a complaint by a senior inspector of Bhadrakali police station, Nashik Police Commissioner Deepak Pandey said.