Police were forced to break up violent illegal raves last night following Boris Johnson's lockdown announcement.
In Yate, near Bristol, members of a 500-strong crowd were violent towards attending officers, Avon and Somerset Police said as they tried to break the event at a warehouse up.
They were called to reports of an illegal rave in a warehouse around 10.30pm on Saturday.
Police including Covid-19 restriction enforcement officers attended, and when members of the crowd began acting violently towards them, rave legislation was enacted to order the crowd to disperse or face possible arrest.
There were no immediate details of any arrests.

In a series of tweets, Avon and Somerset Police said: "Shortly after 10.30pm we were alerted to an illegal rave taking place in a warehouse in Yate. Officers are on the scene.
"Both local units and Covid Enforcement officers are currently engaging with organisers and event attendees. They are being supported by the drone unit. It’s believed up to 250 people are in attendance.
"The latest reports suggest 400-500 people are currently at the rave site. Officers remain at the scene and further support is en route.
"Members of the public have been violent towards officers. Rave legislation has been used, which means that people should leave the area, or will be liable to arrest."

Avon and Somerset Police have been contacted for more information.
There was also a rave in Wigan, Greater Manchester, last night, despite the area being under a Tier 3 lockdown.
Pictures showed huge crowds gather at an area of land west of Rindle Road and north of Astley Road.
There were reports of police helicopters circling the area. A number of roads were reported to have been closed, Manchester Evening News reports.
Pictures from the scene show dozens of police vans were in attendance and one image appeared to show tyres had been slashed on a police vehicle.

Greater Manchester Police have been contacted for comment
Organisers of illegal raves can be fined up to £10,000 while police also have the power to fine people attending illegal events £100.
Last month, a party organiser was handed the huge fine after a rave was busted by police.
Up to 100 partygoers attended the illegal gathering with bouncers, DJs and a buffet defying coronavirus restrictions.
Officers discovered DJ mixing desks, industrial speakers and a buffet spread when they broke up the party just before 11.30pm in Greater Manchester.
The organiser was fined £10k after defying the Government's Rule of Six which bans parties or gatherings of more than six people in England.
Elsewhere, police were called to break up an illegal gathering at a Sussex University campus last night, according to reports.
Eyewitnesses said there was a "large gathering" in the area on Saturday night and a "large number of police" attended.
One person tweeted: "Lots of police on site at Sussex university due to large gatherings of students. Gradually dispersing.
"At least 18-20 police vehicles now at Sussex university."
Another tweeted: "Meanwhile At Sussex Uni campus, Where we know has been large police presence due to gatherings this evening lots of social distancing is taking place. What Hope have we got ?"
The gathering caused outrage on social media.
One person tweeted: "So selfish," while another said: "Covidiots".
Another tweet read: "This is disgusting. There have been problems in the community too and relationships with locals really strained."
Both Sussex Police and The University of Sussex have been contacted for comment.