BERLIN (AP) — 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, officials and local media reported.

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

Police have detained the six.

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.”