Strikes at German low-cost airlines Eurowings and Germanwings led to the cancellation of nearly 400 flights Thursday, stranding some 40,000 passengers, a spokesman for the two companies said.

The airlines, owned by flag carrier Lufthansa, are locked in disputes with the Ufo flight attendants union.

Eurowings staff are calling for salary increases and improved working conditions while Germanwings personnel are unhappy with terms for part-time employees.

Cabin crew stayed away from midnight in Berlin, Duesseldorf, Hamburg, Cologne, Dortmund, Hanover and Stuttgart in what is to be a 24-hour strike, forcing around 400 out of 550 planned flights to be axed.

The largest hubs in Frankfurt and Munich were spared, along with all long-haul flights.

Nicoley Baublies of Ufo defended the decision to hit the two airlines at once with strikes.

‘At the end of the day both have the same targets and the same management,’ he told public broadcaster ZDF.

Another Ufo representative, Daniel Flohr, threatened to extend the strikes next week if the talks failed to make headway.

‘We will strike on two days if management doesn't budge,’ he told AFP, without specifying a timetable.