German airports are to be hit by a ‘warning’ strike.

Trade union Ver.di has called for all-day warning strikes today (Thursday, April 20) and tomorrow (Friday, April 21) for employees in certain parts of the Düsseldorf, Hamburg and Cologne/Bonn airports. So far, the strike action is contained to these three airports.

The strike is expected to start tonight and end on Friday night at unknown times.

The aviation security area, passenger control, personnel and goods control and service areas are expected to be affected.

"Longer waiting times or even flight cancellations are to be expected," the trade union warned.

Hamburg Airport has said all departures will be cancelled or take place without passengers on Thursday and Friday due to the strike, with around 80 000 passengers affected. However, arrivals will still be possible.

Negotiations between unions and bosses on time bonuses for night shifts, Saturdays, Sundays and work on public holidays are said to be behind the strike.