The Government had asked a low-cost airline operator to explain why it had cancelled a flight without informing passengers. The Secretary for Transport and Public Works, Mr Lau Si Io, said the Civil Aviation Authority had instructed that operator to submit a report and include suggestions to avoid a repeat of the incident. Some 120 passengers turned up at Macao International Airport last Sunday to find their flight to Vietnam had been cancelled. Mr Lau said it was regrettable that the cancellation brought inconvenience to passengers. He said the operator should explain and provide assistance to the affected passengers.