A Swiss Air flight from Bucharest, Romania to Zurich made an emergency landing in Austria because of smoke on board. All 79 people, including crew members, have been evacuated.

A Swiss International Air Lines (SWISS) flight was forced to make an emergency landing in the Austrian city of Graz because of smoke in the cabin and cockpit, the carrier said.

The Airbus 220-300 aircraft was headed to Zurich from Bucharest, Romania on Monday when the crew decided to abort the flight “due to engine issues,” the airline said in a statement.

There were 79 people on board flight LX1885, including five crew members. The aircraft landed safely and all passengers were evacuated.

Twelve passengers received medical attention and one cabin crew member was transported to a hospital in Graz by helicopter. Their condition remains unclear.

The other four crew members are also under medical care, the airline said.

Airline working to determine cause of incident

SWISS, which is part of the Lufthansa Group, said it remains in close contact with authorities and is working diligently to determine the cause of the incident.

SWISS said it planned two special flights, with a flight carrying passengers to Zurich set to leave Graz Tuesday morning.