Only 100 of 830 scheduled takeoffs and landings would go ahead as planned due to Thursday’s strikes, an airport spokesperson told AFP news agency.

The airport operator has warned that further cancellations are possible.

Public sector workers took part in walkouts throughout Germany for a range of services. Those included some workers at Hamburg Airport, though the airport said the only flights cancelled were those to and from Munich, reported German press agency dpa.

A union for service workers said ground and security staff made “an indispensable contribution to the safety and reliability of air traffic – around the clock, in all weather conditions”.

The “warning strike” is a common tactic in German negotiations, said the union, used to increase pressure during talks with the federal government and municipal authorities on wages and working conditions for public sector employees.

Hamburg Airport advised travellers to arrive early and with only hand luggage where possible.

The industrial action is expected to end at midnight on Friday.

Earlier this week several unions in Italy held a four-hour pilot walkout.