Flooding which has forced road closures and disrupted travel to Heathrow Airport was caused by a burst main beneath a ring road, it is understood.
Passengers have been asked not to travel by road to Terminals Two and Three after access was blocked by a flood, Heathrow Airport said on Saturday morning.
The Press Association understands the flooding was caused by a main leak beneath Inner Ring Road West, which continues to cause disruption in the central terminal area (CTA).
The CTA refers to an area including Terminals Two and Three, as well as a number of other buildings, connected by a network of roads. The main leak occurred beneath a road in this area.
It is understood that there is no flooding within either terminal, and flights have not been disrupted.
Passengers have been asked to leave extra time to complete their journeys, and to use the Heathrow Express, Elizabeth Line and Piccadilly Line, or park and ride services at Terminals Four and Five to access Terminals Two and Three.
The disruption has hit passengers amid the school summer holidays, which sees hundreds of thousands of customers pass through the airport at peak times.
A spokesman for Heathrow Airport said: “Flooding in the central terminal area has resulted in on-going road closures restricting access to Terminals 2 and 3.
“Passengers travelling to or from either of these terminals today must not travel by road.
“Passengers are strongly advised to use Heathrow Express, Elizabeth Line and Piccadilly Line rail services where possible.
“Any passengers that must travel by car must use Park and Ride, head to Terminals 4 or 5 and take free rail services from there, or change at local rail stations.
“Please allow extra time for your journey. Our teams are working to resolve the situation as quickly as possible, we apologise for any disruption caused.”
