A warehouse party that began on New Year’s Eve and was to last until Tuesday was cut short after a police raid in France.
The illegal party breaching coronavirus rules, had close to 2,500 people in Lieuron near Rennes.
A number of party-attendees were from UK and Spain, police said.
Police made several arrests following clashes. A car car was set on fire and officers brazed throwing objects while attempting to shut the event down. At least three officers were injured.
Police trying to stop the event faced “fierce hostility from many partygoers”, a statement from local authorities said.
Interior Minister Gérald Darmanin said on Twitter that trucks, sound equipment and generators were seized at the scene and an investigation has been opened.
More than 1,200 fines were issued for non-compliance with the curfew, not wearing a mask and attending an illegal gathering, Mr Darmanin said.
On Friday authorities said they had opened a sanitary cordon around the party and anyone leaving the event was urged to self-isolate for seven days.
One of the party-goers, who gave his name as Jo, told the AFP news agency that “very few had respected social distancing” at the event.
On Friday an interior ministry crisis meeting was held and all vehicle exits from the rave were blocked as police sought to shut down the party.
France introduced strict rules ahead of the New Year including a curfew from 20:00 until 06:00.
More than 100,000 police officers were deployed across the country to break up parties and enforce the curfew.
Officers were instructed to break up underground parties as soon as they were reported, fine participants and identify the organisers.
France has recorded more than 2.6 million coronavirus cases and 64,892 deaths since the pandemic began.