Frankfurt Airport was forced to briefly suspend operations and cancel some flights after climate protesters invaded the airfield of Germany’s busiest hub during the peak travel season. 

In total, 140 flights had to be canceled, airport operator Fraport said in a statement. Operations are resuming after Fraport suspended services shortly after 5 a.m. because protesters had glued themselves to a taxiway, the company said. 

Travelers should continue to check the status of their flight before making their way to the airport, a spokesperson for Fraports said.

The disruptions come as Germany enters the peak summer holiday season, with 1,400 planned flights on Thursday. Frankfurt Airport has faced chaotic moments in recent months, including strikes earlier in the year and snowstorms in March that incapacitated major airports across the country. Last week, air traffic around the globe was hobbled by a software glitch that caused major dislocations in air traffic. 

All four runways were back in operation before 8 a.m. local time, and police detained eight demonstrators, Deutsche Presse-Agentur reported. Pictures posted on X showed people sitting on the tarmac to protest against the continued use of fossil fuels.

On Wednesday, protesters also targeted the smaller Cologne-Bonn Airport by gluing themselves to the tarmac. The protests in Frankfurt and Cologne-Bonn are part of an international action that also targeted London Heathrow and airports in Scandinavia, among others. The group similarly disrupted perations in Berlin in late 2022, where they also managed to gain access to the airfield.