German authorities closed down Munich Airport temporarily on Saturday after six climate activists broke through a security fence and glued themselves to access routes leading to runways.

The activists from the group Last Generation were protesting against flying, the most polluting form of transportation, said the German news agency dpa.

Police arrested the six protesters.

Incoming flights had to be diverted to other airports, an airport spokesperson said. After a couple of hours, the airport’s two runways were reopened though some disruptions to flight schedules may happen, a statement on the airport’s official website said.

Last Generation posted on social media platform X, accusing the German government of “downplaying” the negative effects of flying on the environment instead of “finally acting sincerely”.

German interior minister Nancy Faeser slammed the protests and called for them to stop.

“Such criminal actions threaten air traffic and harm climate protection because they only cause lack of understanding and anger,” she wrote on X.

Ms Fraser also applauded police efforts to bring order back to the airport and called for airport safety measures to be checked.

The general manager of the German Airports Association, Ralph Beisel, sharply criticised the climate activists’ actions.

“Trespassing the aviation security area is no trivial offence. Over hundreds of thousands of passengers were prevented from a relaxed and punctual start to their Pentecost holiday,” he told dpa.

Mr Beisel also called for harsher penalties for activists who break into airports.

Climate activities blocked flights at Hamburg and Dusseldorf airports for several hours in July.

In January, Last Generation – known for gluing themselves to streets to block traffic which has infuriated many Germans – said it would abandon the tactic and move on to holding what it calls “disobedient assemblies”.

Their actions have been widely criticised, and Chancellor Olaf Scholz described them as “completely nutty”.