Additional details from another source:
SCOOP EDITORS NOTE: Alison McCulloch says that the release is incorrect insofar as the Domestic Terminal is concerned. This is not open to passengers and passengers have been moved away from windows.
(Further report) The plane is now parked on runway used in north westerly winds quite a way from the terminal. It has some cars around it and some people crouching as if in fear of it blowing up.. Police with dogs are searching the terminal building. And police have said they are searching the plane for a bomb.
wow