Update – all BA shorthaul flights from Terminal 4 have been cancelled for the rest of the day.
And all BA longhaul flights departing from Terminal 4 between 1500 and 2100 have been cancelled.
The move follows on from an earlier evacuation at Heathrow’s Terminal 4 caused by a suspect package.
A spokesperson for BAA said: “A suspect bag was identified shortly before midday in Terminal 4. As an extra precaution, it was decided to perform secondary searches on all departing passengers at the aircraft gate. In order to facilitate the secondary search process, a decision was made by the police to partially evacuate the departure lounge and re-screen the passengers. This process will cause delays to some flights departing from Terminal 4. Contingency plans have now been activated to ensure that we are able to effectively manage the increase in resource that this secondary search requires.”