Police in the UK have arrested more than 50 people after environmental protestors blocked flights in and out of Stansted, London’s third busiest airport.Climate action group, “Plane Stupid” says its demonstration began around four a.m CET when it breached security to occupy a restricted area. The runway was closed for about two hours as a precaution. A film shot by the activists shows how they broke in while the runway was closed for overnight maintenance work. Many of the demonstrators chained themselves to fencing they carried on to the tarmac. One of the activists taking part said the action would stop tonnes of carbon dioxide being released into the atmosphere. The group is opposed to the plans of airport operator, BAA to expand capacity at Stansted and London’s main airport Heathrow. Flights have now resumed but travellers are still being urged to contact their carriers.