Airport officials said the incident occurred on Tuesday night when about 20 passengers were taken by an airport bus to the domestic terminal instead of the international terminal after they alighted from the plane from Kuwait.

The faux pas came to the notice of officials when the passengers asked for their luggage, which awaited clearance at the international terminal.

All the passengers, except one, were soon taken to international terminal for clearance, they said.

A passenger, Eliot D'Sooza, who had only hand baggage, had already left the airport by then.

Airport officials immediately traced him and asked him to return to the airport.

Air India (AI), which is carrying out the ground handling operations at the airport, said an internal inquiry would be launched into the incident.

The AI sources said the flight from Kuwait was expected at 9pm. But it landed here at around 8.30pm and was parked at the 10th parking bay near the domestic terminal.