Police have ended an illegal rave at an old factory in Talywain, Torfaen.
Up to 1,000 people are thought to have attended the 'music event' that started on New Year's Eve.
Residents from five miles away from the site took to social media to complain about the noise from the party in the ETM factory at the site.
Fireworks were also heard at around 5am.
One Talywain resident said she could hear the music at 12am on New Year's Day.
Gwent Police force duty inspector Ryan Francis said the event has now ended and an investigation is underway to identity the organisers.
Police said officers will remain in the area and no arrests have been made.