Heathrow Airport’s Terminal 4 has been evacuated while emergency services respond to a “possible hazardous materials incident”.
An airport spokesperson said the check-in area was closed “while emergency services respond to an incident” and advised passengers not to travel to the terminal in west London.
All other terminals at the UK’s busiest airport are operating as normal.
A London Fire Brigade spokesperson said: “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.”
The spokesperson added: “The brigade was first called about the incident at 5.01pm, and crews from Feltham, Heathrow, Wembley and surrounding fire stations have been sent to the scene.”
Pictures shared on social media appeared to show a number of ambulances outside the airport’s Terminal 4.
National Rail said trains were not calling at Heathrow Terminal 4 due to “emergency services dealing with an incident”.
Eyewitness Paul Scott said he had just checked in and was about to go through security when the evacuation happened.
He told Sky News that everyone who was in the departure hall had been evacuated and passengers were ushered away to about 150 metres from the terminal building.
He said privacy screens had been put up and he saw a number of people in white suits arriving at the scene.
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Mr Scott said a man with a loudspeaker had said it was a specialist team.
He said the mood was fine but it was a little confusing as no-one really knew what was going on.
Mr Scott, who was planning to fly to Sri Lanka on business as part of a group of six, said people have been handing out foil blankets as the temperature was dropping.
Transport Secretary Heidi Alexander wrote on X that she was monitoring updates from those at the scene and the airport.
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