Security workers checking carry-on luggage at Barcelona’s airport began partial strikes Friday, threatening more queuing chaos for passengers at one of Europe’s most popular airports.

Spain’s airport authority, AENA, said that during the first of four strike hours, passengers had to queue for some 40 minutes to get through the security filter but that this dropped to 20 minutes when the stoppage ended.

Barcelona-based newspaper La Vanguardia reported queues of more than an hour long at what is the beginning of one of Spain’s peak summer holiday weekends.

Government-ordered minimum services of 90 percent during the strike hours reduced the effect of the stoppages.

The workers’ union called the periodic stoppages for Friday, Sunday and Monday after talks failed to end the dispute with the private company, Eulen, which runs the service at El Prat airport.

AENA officials met with the representatives of the workers Friday to try to find a solution.

Passengers flying from Barcelona have been suffering delays of several hours to reach the boarding area in recent weeks because of the dispute, which centers on demands for more staff and better salaries. The workers plan an indefinite strike as of Aug. 14 if their demands are not accepted.

The association of Spanish airline companies, ACETA, said some 1,000 people have missed their flights since July 24 because of the dispute.

Barcelona’s airport, like others in Europe, was also affected by major delays in police passport controls following new European Union regulations several weeks ago.

Marti Serrate, president of Spain’s travel agency association Acave, said “people are terrified,” of missing their flights.

“We urge them to go to the airport at least four hours early so as not to get a nasty surprise,” he said, adding that “this shouldn’t have to be tolerated in 2017.”

This article was written by Ciaran Giles from The Associated Press and was legally licensed through the NewsCred publisher network. Please direct all licensing questions to [email protected].

Photo Credit: Negotiations are under way to resolve labor issues at Barcelona's airport. Passengers wait to pass the security control at the Barcelona airport in Prat Llobregat, Spain, Friday, August 4, 2017. Manu Fernandez / Associated Press