India, Dec. 8 -- Budget carrier IndiGo Airlines has told the Directorate General of Civil Aviation (DGCA) that the mass cancellation of flights last week was triggered by a "compounding effect of multiple factors" that struck the airline at the same time.

The aviation regulator, which confirmed having received the airline's response to its notice on Monday, said it was examining the communication and would initiate enforcement action "as deemed appropriate".

DGCA said the airline's letter was signed jointly by the airline's chief executive officer Pieter Elbers, and chief operating officer Isidre Porqueras, and was "profusely apologetic" and "deeply regretted" the inconvenience caused to thousands of passengers. DGCA said it received th...