Airports in Germany were bracing for major disruption on Friday amid a major walkout by ground crew that could affect nearly 300,000 passengers.
The Verdi union said the one-day strike by civil aviation security and ground staff would affect airports in Frankfurt, Munich, Stuttgart, Hamburg, Dortmund, Hannover and Bremen.
Frankfurt and Hamburg airports urged passengers not to come at all. Those travelling within Germany were advised to switch to train journeys. Frankfurt is the country’s biggest airport and a major connecting hub for intercontinental travel.
"The terminals are empty this morning," said a representative for the airport in Hamburg on Friday morning.
"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.
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.
The strike is the latest in a string of walkouts as employees seek improved terms in line with rising cost-of-living expenses.
The Verdi union is demanding a pay rise of 10.5 per cent to counter the effects of high inflation.
"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."
In a statement, the union said: "The strike is expected to have a strong impact, especially on domestic air traffic, ranging from delays to cancellations and even a partial shutdown of air traffic."
German airport association ADV called the strike action "completely unacceptable", saying it would affect about 295,000 passengers and more than 2,300 flights all together.
"Solutions must be found at the negotiating table and not at the expense of passengers," ADV chief Ralph Beisel said in a statement.
Munich International Airport said it had suspended most passenger flights because of the protest action, with contingencies for relief flights and planes for medical, technical and other emergencies.
The move is set to complicate travel plans for delegates attending the Munich Security Conference, a major annual event for defence and foreign policymakers.
Lufthansa said it would cancel at least 1,200 flights scheduled for Friday due to strikes at its main Frankfurt and Munich hubs.
The strike caps a chaotic week for air travel in Germany.
The renewed disruption follows the accidental cutting of telecoms cables on Wednesday that ended up grounding the national airline’s fleet for much of the day.
Meanwhile, several German airports on Thursday said their websites were down due to suspected cyber attacks, the latest instance of online sabotage in the country.
Airports in Duesseldorf, Nuremberg and Dortmund said they were affected, while at least two others were reported to have been hit.
German news outlet Der Spiegel said a group of Russian hackers had claimed responsibility for the attack, although authorities have yet to comment.
The sites were believed to have been targeted by so-called "distributed denial-of-service" attacks, designed to overwhelm the target with a flood of internet traffic, preventing the system from functioning normally.
"The site is being overwhelmed by massive demand," said a representative for Airport Nuremberg. He said it was "uncertain" when it would return to business as usual.