About 70 firefighters are tackling a grass fire in north London.
An area of grassland measuring about 900m by 600m is alight and 10 fire engines were dispatched to the scene on Rammey Marsh in Enfield after being called at 12.59pm.
The London fire brigade (LFB) said the flames were producing a lot of smoke over the M25 between junctions 25 and 26. Its cause has yet to be established.
The LFB reiterated its message to the public not to have barbecues in open spaces and dispose of rubbish and cigarettes properly to prevent fires from starting, with temperatures reaching 34C in southern England.
At about 6pm, LFB wrote on Twitter that “firefighters are continuing to work in hot and challenging conditions at the scene of the grass fire in #RammeyMarsh”.
A spokesperson said: “This summer has seen an unprecedented long, dry spell with high temperatures, so the grass in London is tinderbox dry and the smallest of sparks can start a blaze which could cause devastation.
“Despite our continued warnings over the last few weeks, we know there are still people who are barbecuing in parks, dropping cigarettes out of car windows and leaving rubbish lying around.
“We are asking Londoners to help us protect the city we all love by doing everything you can to prevent further grass fires. Please don’t barbecue in open spaces or balconies, throw your rubbish away safely, and put your cigarettes out properly.”
Fire crews from Chingford, Hendon, Enfield, Southgate and surrounding fire stations are at the scene.
On Thursday, three hectares of grass, shrubs and bushes were destroyed in a blaze in Rainham, east London. It was the second time in two days that the grassland there had caught fire.