Eleven police officers were injured in western France on Saturday as they broke up a 1,500-strong illegal rave with one party-goer losing a hand in the clashes.
Police fired teargas to disperse the crowd, who defied an 11:00 pm coronavirus curfew on Friday and stayed on well into Saturday afternoon in the area around a racecourse near Redon in Brittany.
"There were very violent clashes when 400 police intervened," said police prefect Emmanuel Berthier, adding the violence lasted more than seven hours through the night.
Police detained five men and opened an inquiry into violence against people in positions of public authority.
By 5pm Saturday, the rave was finally shut down as the sound system and loudspeakers were reportedly destroyed by the police.
According to the authorities, 11 police officers were injured, two of whom were taken to hospital.
Two of the ravers were also hurt, including a 22-year-old man who lost a hand.
Firebombs, metal balls, breeze blocks
"People had an objective, to confront the forces of public order," said Berthier, citing the use of Molotov cocktails, metal balls and breeze blocks thrown at police.
One police officer said it was "not usual" for people to bring the metal pétanque balls to a rave.
Meanwhile, event organisers said police had chosen violence instead of dialogue by firing tear gas.
Local authorities had banned the party on Friday, which came two days before the coronavirus curfew is set to be lifted as Covid-19 case numbers fall in France.
In memory of Steve Caniço
The rave had originally been set up in memory of a young man killed in the nearby city Nantes two years ago during the annual nationwide Fete de la Musique celebration.
Prosecutors said Friday that Steve Maia Caniço fell into the Loire river when police moved in to break up the gathering.
His body was found more than a month later and protesters in Nantes have demanded "Justice for Steve", saying the police intervention was disproportionate.
Hundreds of people flouted France's coronavirus curfew with underground parties near Dijon and a village in western Brittany, while police managed to prevent organisers from staging a major rave in Paris.