Lufthansa cancelled 290 flights today due to cabin crew strikes, around 10% of its total flights.
The cancelled services include 15 intercontinental flights to and from Frankfurt and Dusseldorf.
But the airline said there would be no cancellations to intercontinental services tomorrow (Saturday).
Flights to and from Munich are not affected, nor are flights operated by Lufthansa CityLine, Germanwings, Eurowings, Air Dolomiti, Austrian Airlines, SWISS and Brussels Airlines.
"Lufthansa will do its utmost to keep the effects of a strike to a minimum and to inform passengers as soon as possible," it said on its website.
"For that reason, Lufthansa requests all passengers early on to stay up-to-date by checking the flight status on LH.com."
Lufthansa is drawing up contingency plans for the rest of the week, as the industrial action is expected to continue.
