Some 87,000 passengers will be affected as airport ground staff in Germany join a strike on Wednesday, called by the country's biggest services union.
More than 1,000 flights have been cancelled because of the strikes at Frankfurt, Munich, Duesseldorf, Cologne/Bonn, Dortmund and Hanover airports, officials from Lutfansa said.
Workers from ground services, security checks, fire fighting and check-in staff joined the strike, severely impeding operations in German airports, hindering 60 percent of the daily air traffic.
The workers in Munich will strike all day on Wednesday, while in Frankfurt, Germany's largest airport, the strike is due to end at 1300 GMT.
Airport operator Fraport has warned it could take a day or two for services to return to normal.
Munich airport said around 700 of a scheduled 1,100 takeoffs and landings had been cancelled.
In Frankfurt, where the stoppages would last until 3:00 pm, some 350 flights and 33,000 passengers would be grounded.
Union Verdi which represents a wide range of public sector workers across Germany, a total of 2.41 million people, identified the strikes as “warnings”.
Lufthansa blasted the walkouts.
"We are not involved in the dispute, but we're being affected the most," the carrier complained.
"It is unacceptable that our passengers are the ones feeling the effects of the strike," said Lufthansa's personnel chief Bettina Volkens.
"Verdi is hurting an airline that offers its workforce the highest welfare standards," she added.
Verdi chief Frank Bsirske defended the move in an interview with daily Sueddeutsche Zeitung, saying the strike was to speed up wage negotiations.
"I hope that this signal will be understood and that an agreement will be reached in the third round (of talks) on Thursday and Friday," he said.
Similar strikes have taken place this week at street cleaning services, schools and swimming pools.
Lufthansa has been repeatedly hit by strikes over the past year in wage disputes of its own, with both pilots and cabin staff staging a number of walkouts over pay and early retirement provisions.
Despite the protracted industrial disputes and the Germanwings crash, Lufthansa saw its profits soar last year on the back of low oil prices and booming passenger business.
Investors mostly took the news of more strikes in their stride and Lufthansa shares were showing a modest loss of 0.1 percent in early afternoon trading on the Frankfurt stock exchange in a slightly softer market.