India’s aviation regulator on Saturday fined IndiGo a record 222 million Indian rupees ($2.45m) for poor pilot roster planning that led to mass flight cancellations in December.

The regulator also issued warnings to senior personnel, including to Chief Operating Officer Isidre Porqueras and to Jason Herter, senior vice president of operations control centre, with directions to IndiGo to relieve Herter “of current operational responsibilities”.

A government source said the fine was the largest to date.

IndiGo has been ordered to provide a bank guarantee of $5.51m in favour of the Directorate General of Civil Aviation, to ensure “compliance with the directives and long-term systemic correction,” the regulator said.

IndiGo said in a statement that the board and management were “committed to taking full cognisance of the orders and will, in a thoughtful and timely manner, take appropriate measures”.

India’s largest airline cancelled about 4,500 flights in the initial weeks of December, leaving tens of thousands of passengers stranded all over the country and leading to chaos at airports.