An overnight protest by climate activists at Leipzig/Halle Airport in eastern Germany forced a three-hour halt to cargo flights, officials said on Thursday.

The protest by the Last Generation (Letzte Generation) group followed demonstrations last week at Cologne-Bonn Airport and then at Frankfurt Airport, Germany's busiest, which significantly disrupted passenger flights.

Federal police said five activists attached themselves to the ground inside the airport perimeter shortly after midnight, and another two were prevented from doing so, German news agency dpa reported. They were removed at about 5 a.m. Last Generation said they didn't set foot on the runways.

Leipzig/Halle is an important air freight hub. Airport spokesperson Uwe Schuhart said air cargo movements had to be suspended for about three hours starting at 12:30 a.m.

There didn't appear to be a significant impact on passenger flights, which don't arrive and depart during the night. The airport's website showed the first plane leaving at 5:41 a.m., about 15 minutes late.

Activists demand Germany abide by climate rules

Police said the activists, who had cut a hole in the perimeter fence, were detained.

Last Generation is demanding that the German government negotiate and sign an agreement on a global exit from the use of oil, gas and coal by 2030.

Last month, the German Cabinet approved legislation that would impose tougher penalties on people who break through airport perimeters.

The bill, which still requires approval by lawmakers, foresees punishment ranging up to a two-year prison sentence for people who intentionally intrude on airside areas of airports such as taxiways or runways, endanger civil aviation, or enable someone else to.

Currently, such intrusions only draw a fine.