Rumours started circulating online accusing members of the Roma community of trying to abduct children, sparking unfounded revenge attacks.
Vigilante groups have launched several attacks on Roma communities in the area around Paris following false reports on social media relaying rumours a child kidnapping operation.
Police in Paris started debunking the story on Monday, tweeting that a claim that a white van circulating between the cities of Nanterre and Colombes to kidnap young women was "Fake News."
"Following the sharing of this rumour on social networks, two people have been unfairly accused and lynched. Do not relay this false information," it added. It reiterated its call on Tuesday, urging people not to spread the rumour so as to "not incite violence."
March 17 attack
The warnings followed an attack on March 17 when a crowd gathered around a white van parked in Colombes, a suburb town north-west of Paris, and beat the two men inside accusing them of being on the lookout for children to kidnap and traffic.
According to the AFP news agency, at least two other violent incidents targeting the Roma community also took place that night in Clichy-sous-Bois and in Bobigny, two suburb towns northeast of the French capital. Some 20 people were arrested following the attacks, AFP reported.
Such rumours have become increasingly common in France. In November 2017, authorities in the Loiret, some 100 km south of Paris, also had to debunk a rumour that a white van driving around the area had been at the centre of several alleged kidnapping attempts after a picture of a vehicle was shared on social media, clearly showing its licence plate.
In November 2018, an 11-year-old girl in Yvelines, east of Paris, told police a man driving a white van had tried to abduct her before admitting that she had lied.
'Slanderous fake news'
But this new rumour concentrated in the Greater Paris area spread like wildfire on social media with users posting images and videos of vans they say are driven by men of Romanian origin. They accuse them of trying to abduct children to harvest their organs or to be part of a sex trafficking ring.
Other videos, which Euronews could not independently verify, show men attacking the vans and their occupants.
And the authorities have so far been unable to quell it. The city of Bondy, north-east of Paris, issued a statement two weeks ago, dismissing as untrue the rumour of a girl's abduction.
"The city had to react because this slanderous fake news targets people in precarious situations and without the means to respond," it said.
Despite these, a local football club warned parents on Facebook on Monday that "several alerts have been made about people who roam near stadiums (usually in vans) on training days to abduct children."
'Racist fake news'
In a statement on Tuesday, the Roma group "Voices of Roma" denounced this "racist fake news" and said the attacks on members of the community had left many "seriously injured and thousands of people scared."
"These racist stereotypes about Roma child abductors date back to the Middle Ages in France and have already sparked crises of deadly violence," it said.
"The same false mechanisms of dehumanisation that led to the massacres of the Rohingya in Burma or the Peuhls in Mali are at the root of these murder attempts in France," it added.