German activists glued themselves to a runway at Munich airport Saturday and caused dozens of flights to be cancelled, in their latest action aimed at pushing authorities to tackle climate change.

The activists from the Last Generation environmental protest group forced their way into Germany's second-busiest airport by cutting through a fence in the early hours, an airport spokesman said.

Flights were suspended, leading to the cancellation of 61 take-offs and landings, he said.

The action came to an end with the arrest of eight climate activists, police told the local public broadcaster.

Both airport runways have been open again since 7:20 am (0520 GMT) but disruptions are expected to continue throughout the day. It came at the start of a long weekend in Germany, which is a busy day for travel.

Last Generation are known for mounting eye-catching protests -- from gluing themselves to busy roads, to flinging mashed potato at a Claude Monet painting -- which have sharply divided public opinion and brought increasingly tough responses from authorities.

Transport Minister Volker Wissing condemned the action, saying it was "not a legitimate protest, but a targeted intervention in air traffic."

"If air traffic is not safe, people are put at risk, major economic damage is threatened and thousands of travellers are stranded."

But in a post on X, formerly Twitter, Last Generation accused the government of not doing enough to discourage people from flying, a major source of climate-damaging emissions.

"It is absurd that people are more likely to be able to afford flights than train journeys," the group said. "The responsibility for this lies with the government: it subsidises flights while the railways are being cut to the bone."

In December 2022, activists from the group had also glued themselves to a runway at Munich airport but caused only minor delays.