Heathrow Airport has warned access to Terminals 2 and 3 is restricted because of flooding caused by a leak in a pipe within the grounds of the airport.
Water in the central terminal area means anyone trying to travel to or from either of these terminals cannot travel by road. Instead passengers are being advised to travel by rail and Tube and to avoid using cars.
An airport spokesperson said: “Our teams are working to resolve the situation as quickly as possible, we apologise for any disruption caused,” adding: “The leak has been isolated and repairs are on-going.”
The disruption comes during the school holidays, one of the busiest periods for the airport.
Heathrow said 19 July was its busiest day of the year so far as many schools broke up for summer, with 267,000 passengers passing through.
The airport was recently affected by disruption to railway services, after a water leak prompted the closure of a tunnel.