A 24-hour strike at seven German airports on Friday was set to affect almost 300,000 passengers as unionised workers press their demand for high wages.
"The terminals are empty this morning," said a spokesperson for the airport in Hamburg, adding that very few of the 32,000 passengers affected had turned up.
Around 295,000 passengers are affected by the cancellation of some 2,340 flights at Bremen, Dortmund, Frankfurt, Hamburg, Hanover, Munich and Stuttgart airports, according to the ADV airports association.
"When we look at the airport terminals this morning, it reminds us more of the worst days of the coronavirus and less of a warning strike," ADV's Ralph Beisel told broadcaster Bayerischer Rundfunk.
German trade union Verdi announced the strike on Wednesday after it said collective bargaining efforts for ground service staff, public sector officials and aviation security workers had made little progress.
"If nothing is done about pay now, we will all be in for another chaotic summer," Verdi Deputy Chair Christine Behle told Inforadio on Friday. "It's about sending a really strong signal."
The strike coincides with the 59th Munich Security Conference (MSC).
Romania's foreign minister, who was set to arrive on one of the cancelled flights, will fly to Austria instead and then make the more-than-four-hour drive to Munich, a Romanian embassy official said.