LONDON, September 8. /TASS/. Passengers and staff at Terminal 4 of London Heathrow Airport have been evacuated following an alleged incident involving hazardous materials.

"Terminal 4 check-in has been closed and evacuated while emergency services respond to an incident," the airport said on X. The London fire department added that the matter might involve hazardous substances, though neither provided further details.

Eyewitnesses have shared photos of ambulances arriving at the terminal. As a precaution, trains are currently passing through the Terminal 4 station without stopping.

All other terminals at the European air hub are operating as usual.