NEW DELHI: India’s aviation regulator on Saturday fined IndiGo a record $2.45 million, issued warnings to senior executives and directed the airline to remove the head of its operations control from his duties after mass flight cancelations last month.

India’s largest airline scrapped about 4,500 flights in the first weeks of December, stranding tens of thousands of passengers nationwide and highlighting concerns over limited competition in the world’s fastest-growing ‌aviation market.

The airline ‌has acknowledged that poor pilot roster ‌planning was ⁠the ​main cause ‌of the disruption. A probe by the Directorate General of Civil Aviation (DGCA) found several deficiencies at the airline after stricter pilot rest and duty rules came into effect last year, the regulator said in a statement.

IndiGo, which holds 65 percent of India’s domestic market, failed to properly identify planning gaps or maintain adequate operational buffers, the DGCA said, adding that the airline had ⁠an “overriding focus” on maximizing the use of crew, aircraft, and network resources.

“(IndiGo’s) approach compromised roster ‌integrity and adversely impacted operational resilience,” the ‍DGCA said.