BERLIN: Berlin Brandenburg Airport said on Thursday it had to close its takeoff and landing runways because of the unauthorized entry of too many people, while a climate change action group claimed its activists had chained themselves to the runway. Also Read: Egyptian minister's son Ramy Fahim sued in US Activists urged people to stop flying and the government to stop subsidizing it, according to a statement released Thursday by environmental advocacy group Last Generation. Also Read: Channel tragedy has left Iraqi family inconsolable We came into contact with several people who had previously gained unauthorized access, and some of them had entrenched themselves in an airport area not accessible to the general public, Berlin police said on Twitter. Also Read: Greece swaps rescued migrants from the high seas According to an airport spokesman, police detained the activists, but the runway was closed so that staff could look for the presence of any additional people. The spokeswoman was unable to specify the number of flights affected.