Airports around the world suffered major technical problems Thursday connected to a temporary failure of a system for checking in passengers and luggage.

Paris, Zurich and Frankfurt airports said they had suffered problems with computer systems, but they had been quickly resolved.

Frankfurt airport confirmed in a tweet that Lufthansa and its partner airlines could not check in luggage during a 20 minute period.

Southwest Airlines said it experienced computer troubles at several U.S. airports. It said the problems had since been resolved and it did not expect any delays.

British Airways confirmed that its online check in system was down, but said flights were operating normally.

Australian carrier Qantas also reported that it had suffered an outage of its passenger booking system.

“Amadeus — a check in system for passengers — went down and now has come back up. Check in was resumed quite quickly,” said Qantas spokesman Stephen Moynihan.

Amadeus operates software that underpins booking systems and other operations for airlines. It confirmed Thursday that it had suffered a “network issue.”

“Amadeus technical teams took immediate action to identify the cause of the issue and restore services as quickly as possible,” it said in a statement. “That action is ongoing with services gradually being restored.”

CNN has confirmed that the following airlines and airports have been affected:

Airlines:
Air France
Southwest
China Air
Qantas
Korean Air
Lufthansa
British Airways

Airports:
Incheon, Seoul
Haneda, Tokyo
Charles de Gaulle, Paris
Zurich
Frankfurt
Gatwick, London
Heathrow, London