More information at: http://www.bbc.co.uk/news/uk-england-london-33503167
Planes at Heathrow Airport have been disrupted after protesters cut through a fence and got on to a runway.
Direct action group Plane Stupid said 13 demonstrators opposed to the airport's expansion plans got on to the northern runway at 03:30 BST.
Six protesters have been arrested on suspicion of Aviation Act offences, police said
The runway was closed for nearly three hours and 13 flights were cancelled.
The airport apologised for the disruption caused and advised passengers to check with their airlines before they travel.
The group behind this are known as "Plane Stupid" and their twitter account is: https://twitter.com/planestupid
What are your thoughts on this? Fantastic idea or stupid? In my opinion it's stupid because the delays they are causing for the planes are in the air would go into holding pattens which means they are going to be dumping more fuel rather than landing at Heathrow but that's my view anyway.