Around 100 firefighters have rushed to the scene of a grass fire in west London, with smoke seen billowing across a Heathrow Airport runway.
At least 15 fire engines have been deployed to the scene in Feltham, London Fire Brigade (LFB) have said.
An LFB statement said: "Fifteen fire engines and around 100 firefighters are tackling a grass fire on Hatton Road in Feltham.
"Around six hectares of land is alight, including standing crop, a field, parkland, grassland, a cemetery and an animal sanctuary.
Smoke bellows from the fire in Feltham Twitter/AnindyaGunaOrig
Around six hectares of land was alight London Fire Brigade
"The Brigade's 999 Control Officers have taken more than 30 calls to the fire."
Station Commander Paul Casey, who is at the scene, said: "The fire is producing a large amount of smoke. Residents in the local area, particularly around Bedfont Sports Club, should keep their windows and doors closed."
The LFB continued: "The Brigade was called at 1453pm.
"Fire crews from Feltham, Chiswick, Heathrow, Heston and surrounding fire stations are at the scene.
"The cause of the fire is not known at this time."
A Heathrow Airport spokesman said: "Due to an off-airport fire, we have alternated our runways this afternoon.
"The fire is not impacting the operation and flights are continuing as scheduled."