Hundreds of revellers were taking part in a suspected illegal rave today after a stand-off with riot police.
Several police officers were hurt after bottles were thrown during clashes with a crowd of up to 500 people at a disused building in central London.
Although police tried to disperse the gathering, most of the people at the scene in High Holborn went back inside the building and carried on with the rave.
A spokesman for the Metropolitan Police said the event was "ongoing" and officers were maintaining a watching brief.
At least seven people had been arrested for suspected public order offences.
Police were first called to High Holborn at 11.20pm yesterday.
Some people in the crowd became aggressive after they were asked to leave the area, police said.
Commanders then called in dozens of riot squad officers from the force's Territorial Support Group.
A Met spokesman said: "Most of the people are still there. They have gone back inside the building, and are going ahead with the rave.
"Officers at the scene have a watching brief."
It is not known when the gathering will break up, but similar events have been known to run on well into the morning.
The injuries to police officers have been described as "minor stuff".
One suffered non-serious cuts to the head.
The Met said bricks were also thrown at officers as they attempted to disperse revellers. A number of buildings and vehicles were also damaged.
Three people ended up needing hospital treatment, the force added.
One was the police officer with what was described as a minor head injury. He was discharged.
A woman in her 30s who police said was caught up in the disorder was also taken to hospital with a cut face, while a man in his 20s needed treatment for intoxication.
Police have surrounded the eight-storey building, which is bordered by High Holborn, Museum Road and New Oxford Street, while the rave takes place.
Road closures were also in place around the site.
The rave continued into the morning with deafening hard techno pumping around the surrounding streets.
Hundreds of revellers spilled out onto New Oxford Street, many dressed in Halloween costumes.
Police kept watch but the atmosphere was friendly.
Samanta Coletti and Flavia Pickler, from Brazil, tried to have their picture taken with some officers.
The pair of experienced ravers were armed with earplugs, water and fake blood.
Miss Coletti, 27, a waitress living in west London, said: "We love it. We always go to squat parties, you never find fights, if someone is stealing or harassing girls they are told to leave, you can leave your bag on the floor and dance."
Miss Pickler, 28, dressed as a toffee apple with her face paint fading away, came on the train from Brighton where she works as a nanny.
She said: "It's very friendly, you can trust people."
Inside the space was dark. Some people were dancing, others were barely moving.
Up on the roof one raver lowered himself over the ledge, obscuring graffiti which read "F*** the police."
But he soon pulled himself back up.Reuse content