Ground staffs at Lufthansa, Germany’s biggest airline are staging a several-hour strike that has prompted the company to cancel hundreds of flights.

The ver.di union called workers at several airports including Frankfurt and Munich out on a so-called warning strike ahead of wage negotiations. The walkouts started Thursday at 4 a.m. (0300 GMT; 11 p.m. Wednesday EDT) and are to continue until late morning.

Ahead of the strikes, Lufthansa cancelled nearly 700 flights including much of the morning’s domestic and European flight schedule.

The union and Lufthansa are to meet Friday to discuss ver.di’s demand for a 5.2 percent increase over the next year for 33,000 Lufthansa employees. Ver.di says Lufthansa’s call for a two-year pay freeze until January 2015 and the extension of the work week by an hour is unacceptable.

More In: International | News | World