Firefighters are battling a large grass fire close to Heathrow Airport.
Five hectares – about the size of four football pitches – of grass and scrubland caught light in Feltham on Saturday afternoon.
A spokeswoman for London Fire Brigade said the long stretch of dry weather was a probable cause of the fire.
Fifteen fire engines were deployed to try and bring the blaze – which is close to Faggs Road – under control, but the fire was still burning by 7.30pm.
The spokeswoman was unable to say when the fire would be out, adding “grass fires are very unpredictable”.
There have been no reported injuries.
A spokesman for Heathrow Airport said the fire had had “no impact” on its operations and both runways are operating normally, with no delays due to the incident.