A dispute between German airline Lufthansa and its cabin workers could ground hundreds of flights across Europe Friday.

The union representing about 12,000 of the airline's flight attendants called the strike Wednesday after talks over pay raises and the outsourcing of some jobs fell apart.

Lufthansa officials warned the strike could ground up to two-thirds of its nearly 1,800 daily flights.

Already, the carrier has annouced cancelations impacting flights across Germany, Europe and the United States.

Lufthansa's website is listing numerous domestic flight cancelations at airports in Frankfurt, Berlin, Munich, Dusseldorf, Hamburg and Stuttgart.

Flights to London, Paris, Moscow, Istanbul and Boston have also been canceled.

A statement on Lufthansa's website says the airline will do its “utmost best to minimize the impact on its customers.”

The carrier is also offering customers traveling within Germany to exchange their plane tickets for train vouchers with Deutsche Bahn.