Hundreds of revellers have gathered at an illegal party in east London despite lockdown measures, police say.
Pictures and videos posted on Snapchat show large crowds gathered in Detmold Road, Clapton, as a DJ plays in the street.
At around midnight on Sunday, Hackney Police said officers were at the scene and a police helicopter was also being used.
In a tweet, it said: "There is a large scale unlicensed music event in a residential street in E5 involving many hundreds of revellers.
"@NPASSouthEast are providing aerial support to officers on the ground."
More Snapchat footage shows police cars and officers at the scene as it becomes dark outside.
Videos and photos posted on Twitter also show large crowds gathered on Hackney Marshes earlier on Saturday.
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In one video, a man says: "Check this out, there's a party going on in the park. There's like a DJ down this side."
Crowds were seen at a number of beauty spots in England on Saturday as many took advantage of the warm weather.
Large groups were spotted at Clapham Common in south London, while many people were also seen on Bournemouth beach.
At Durdle Door, near Lulworth, three people were seriously injured after jumping off cliffs.
An air ambulance was called and large crowds had to be moved from the beach to allow the helicopter to land.
The public has been warned not to go beyond official guidance as lockdown measures are eased further on Monday.
England's deputy chief medical officer Professor Jonathan Van-Tam said now is a "very dangerous moment" and that the public and the government have a "dual responsibility" to prevent a second wave of COVID-19.
Speaking at the government's daily briefing, he warned: "Don't tear the pants out of it, and don't go further than the guidance actually says."
From Monday, people will be able to meet in groups of up to six outside, as long as they stay two metres apart.