We've just had a statement from the London Fire Brigade which says: "Firefighters are responding to a possible hazardous materials incident at Heathrow Airport. "Specialist crews have been deployed to carry out an assessment of the scene, and part of the airport has been evacuated as a precaution whilst firefighters respond.

Police carrying out enquiries after Heathrow Airport terminal evacuated ‘but no trace of any adverse substance found’

London’s Heathrow Airport reopened after Terminal 4 was evacuated due to a suspected hazardous materials incident. Emergency services found no harmful substances. Around 20 people reported minor injuries.