Police near Paris have intervened to break up a middle-of-the-night house party attended by an estimated 300-400 people in a blatant flouting of health rules in the midst of the country's second lockdown.
The organiser of Friday night's illegal festivities and the house owner have both been taken into custody, AFP reports on Sunday quoting police sources.
Alerted by neighbours at Joinville-le-Pont in the Val-de-Marne department, police were set upon by "clearly inebriated" party-goers who threw bottles at them, according to the police headquarters.
Officers used special grenades to disperse the revellers. One man was injured and taken to hospital where he was tested positive for COVID-19, police say.
On Saturday afternoon they called on those who had been present to get themselves tested as soon as possible and self-isolate until they receive the results.
The public prosecutor's office says an investigation has been launched into violence against public officials.
The party in the southeastern Paris suburb drew French media attention because of its size and the chaos that reportedly reigned at the house. Le Parisien said the property was equipped with a pool, a sauna and a dance floor, and was regularly rented out.
A fight on the dance floor was already in progress when police arrived, the newspaper reported. The party had been advertised on social media.
Another "clandestine", smaller private party days earlier in southwest France grabbed headlines because it was held by nearly two dozen medical interns.
Police broke up the gathering at their residence at Bigorre Hospital in Tarbes at about 4 a.m. on Wednesday. The party-goers were dressed down by superiors and are awaiting eventual punishment.
Police are out in force around France to enforce the rules of a national lockdown which began two weeks ago and is expected to remain in place at least until early December.
People are only allowed to leave their homes for specified reasons such as work, essential shopping or brief exercise. Schools remain open, in contrast to last spring. Widely seen as a lighter version of France's spring lockdown, the renewed restrictions have been taken less seriously by some.
French hospitals are stretched and delaying some operations to tend to COVID-19 patients.
The latest figures published by the French health authorities show the number of hospital admissions and deaths from coronavirus have been continuing to rise. As of Saturday, the number of fatalities since the outbreak began was put at over 44,000.