A Bengaluru-bound IndiGo flight carrying 180 passengers returned to Mumbai airport soon after take-off on Tuesday night following an alleged engine failure, The Times of India reported. A full emergency was declared on board and engines and ambulances were kept on stand-by when the plane made a landing in Mumbai.

“IndiGo flight 6E 565 faced a technical issue while it was airborne,” the airline said in a statement. “Following the standard operating procedures, the pilots immediately took the precautionary step of returning to Mumbai for necessary checks. An alternate aircraft was provided for completion of the flight.”

The matter has been brought to the notice of the Directorate General of Civil Aviation and is being investigated, IndiGo added.