LONDON, Feb. 25 (UPI) -- Greenpeace protesters climbed atop a British Airways jetliner Monday to protest plans for a third runway at London Heathrow Airport.
The four protesters unfurled a banner reading "Climate emergency -- no third runway" on the Boeing 777's tail, CNN reported.
The activists waited until all passengers left the aircraft from Manchester, England, before walking through the terminal doors, crossing the tarmac and climbing stairs onto the fuselage, Sky News reported.
The four were taken down on an airport cherry-picker and taken away by police. Airport operations were unaffected.
One protester, Anna Jones of Leeds, England, told Sky News: "I am standing on this plane because our planet and the people who live on it are in danger. Climate change can be beaten but not by almost doubling the size of the world's biggest airport."
British Airports Authority, which operates Heathrow, said it would investigate the incident.
"There is an important debate to be had regarding airport expansion and BAA respects people's democratic right to protest lawfully," a BAA-Heathrow spokeswoman said. "However, direct action on the airfield is unlawful and irresponsible."
The demonstration was two days before the British government's public consultation on whether a third runway should be built.