Firefighters in London have issued an urgent safety warning and said they are "praying for rain" after a large grass fire in east London.
More than 220 firefighters attended the blaze on Wanstead Flats in Redbridge on Sunday.
London Fire Brigade (LFB) said it was the largest grass fire in its history.
Commissioner Dany Cotton has urged the public to take care amid the heatwave and said dry conditions can see fires "spread like lightning".
Huge plumes of smoke were seen across the capital as LFB received more than 110 calls to the area on Sunday afternoon.
About 100 officers remained at the scene on Monday to keep the smouldering land under control.
'Like a tinderbox'
Ms Cotton warned people not to drop cigarettes out of car windows or have barbecues on dry grass because such fires can spread quickly.
"This weekend we dealt with the largest grass fire in our history," she said.
"The ground is extremely dry at the moment and grassland and parks will act like a tinderbox when exposed to even the smallest of sparks.
"I never thought I'd say this but we are praying for rain," she added.
The LFB said no-one was hurt and no property was damaged in the Wanstead blaze, which was the same size as 100 football pitches at its peak.
#NPAS61 assisting @MPSRedbridge @MPSWForest @MetTaskforce and other officers from @metpoliceuk keep members of the public safe while road closures and diversions were put in place to allow the @LondonFire attend and deal with a large grass fire on Wanstead Flats. #Teamwork pic.twitter.com/EZ85QSJWhW— NPAS London (@NPASLondon) July 15, 2018
The fire service said it had been called to more than 20 grass fires so far this month.
At the weekend 100 firefighters attended a large grass fire in Feltham, while three LFB engines were sent to help Essex crews with a huge blaze in Ockendon.
There were also smaller grass fires in Woodford Green and Richmond on Sunday.