Climate protesters glued themselves to a runway at Munich airport on Thursday morning and also managed to storm a runway at Berlin-Brandenburg, airport authorities said.
In Munich, four activists spent around 45 minutes glued to the airport's northern runway before they were dislodged and arrested, a spokesman for the airport said.
"We were able to handle all our arrivals and departures via the southern runway, which resulted in minor delays but no cancellations," the spokesman said.
The activists have since been taken into custody and flight operations have returned to normal, he added.
At Berlin-Brandenburg airport, a spokesman said "several people" had made their way onto a runway but there was no impact on flight operations.
The Last Generation environmental protest group said in a statement that it had carried out the protests in opposition to "a major state-subsidised contributor to the climate catastrophe".
"We can no longer stand by silently as a few rich people drive the world into the abyss on behalf of all of us and devastate our common livelihood," spokeswoman Aimee van Baalen said.
Last Generation has carried out a series of increasingly eye-catching stunts in Germany over the past few months, drawing criticism from politicians.
In October, members of the group thew mashed potatoes over a glass-covered Claude Monet painting in Potsdam and glued themselves to an exhibition of a dinosaur skeleton at Berlin's Natural History Museum.
Traffic at Berlin-Brandenburg airport was temporarily suspended in November due to a protest by the group.
Activists from Last Generation also drew controversy in November when they apparently prevented emergency workers from getting to the scene of an accident.
The government has warned climate activists not break the law, with Chancellor Olaf Scholz describing the stunts as "misguided".
Activists of "Letzte Generation" (Last Generation) glued themselves to the tarmac of the airport to protest (REUTERS)