As many as 3,000 people are thought to have travelled to an illegal rave in Wales today, despite new rules to crack down on mass gatherings in Britain due to the coronavirus pandemic.
Officers are at the scene in Banwen, Neath Port Talbot and South Wales Police have condemned the "totally unacceptable" event.
It comes after police in Norfolk, England worked to shut down an all-night unlicensed music event in a forest attended by more than 500 people.
Norfolk Police described the organisation of a large gathering in Thetford Forest, which began late last night, as "extremely disappointing".
Dozens of officers, some holding protective shields, faced off with the revellers but despite a few scuffles, the party was largely dispersed peacefully.
Meanwhile, thousands of pounds worth of equipment was seized by UK police ahead of an unlicensed music event the force said was due to take place in Harlow, Essex yesterday afternoon.
The British government introduced tough new measures on Friday to target "serious breaches" of Covid-19 restrictions, including £10,000 fines for illegal mass gatherings.
South Wales Police said that two alleged organisers of the illegal rave have been handed fixed penalty notices for £10,000
Around 1,000 people remained at the site this evening, the force said.
Additional reporting by Reuters
