The plane, carrying 147 passengers and six crew members, had to make an unscheduled landing in Geneva late on Saturday night to allow four people to be taken to a local hospital for treatment, a Lufthansa spokeswoman said.

The other 10 were given first aid at the airport.

Several passengers were thrown into the air, hitting the ceiling of the Airbus A321. A food trolley was also thrown into the air, witnesses said.

Among the passengers on the Munich to Lisbon flight were the president of the Portuguese parliament, Jaime Gama, and Portuguese singer Dulce Pontes.

"There was no warning. Among the injured were crew members, as well as those passengers who had undone their seat belts," Gama told Lisbon newspaper Publico. "I was not afraid, but it was a strange feeling to watch the drinks trolley fly through the air," he said.

Lufthansa, Germany's flagship airline, sent a replacement craft from Frankfurt to continue the flight to Portugal.