Up to 90 police officers were confronted by 200 people at an illegal rave on an industrial estate.
Bottles, coins and pallets were thrown at Thames Valley Police officers as they tried to gain access to a warehouse in Deans Road, Old Wolverton, Milton Keynes, where the rave was taking place.
A police spokesman said some officers had a car driven at them at speed and another officer was confronted by 30 people while he was on his own after the rave was discovered at about 1.30am on Sunday.
With the help of the Chiltern Air Support Unit the rave was shut down at about 4am. One person was arrested on suspicion of criminal damage, police said.
Superintendent Nikki Ross, local policing area commander for Milton Keynes, said: "Various warehouses in the city have been used by rave organisers already this year and my officers were patrolling to ensure none would take place on Saturday night when they identified this one in the early hours of Sunday.
"However, when they attempted to bring it to a close they were confronted with a number of people intent on committing violent disorder.
"I would like to applaud the bravery of my officers, who were confronted by around 200 people who were throwing bottles, coins and pallets.
"Some officers had a car driven at them at speed and another single officer was confronted by around 30 people intent on violence.
"They arrived at around 1.30am and the rave continued inside the warehouse while the disorder took place outside until we managed to gain access at 4am.
"The message is simple: we will not allow Milton Keynes to become a place where illegal raves take place and anyone who thinks they can come to the city, trespass on private property and organise a party can expect to be dealt with severely.
"This event was unannounced and planned to take place on private property."
Anyone who saw the organisers arrive, or who witnessed any of the disorder, should call Detective Inspector Nick Glister on 101.
PA