Roma leaders in Paris have called for police protection after a series of vigilante attacks sparked by false reports of attempted child abductions.

Police arrested 20 people after attacks on Roma on Monday night in suburbs north-east of Paris that followed false rumours spread on messaging apps and social media warning of kidnappings.

“We are calling today on the interior ministry ... for immediate protection by way of round-the-clock police presence,” Anina Ciuciu, a spokesperson for the Voice of Roma group, told RMC radio.

She said the reports were “a revival of the medieval stereotype” of Roma in which “Gypsies are likened to thieves and child-catchers”.

The attacks appear to have been sparked by the re-emergence of a longstanding online hoax in which people warn of a white van being used in attempted kidnappings of young women or children.

Police have renewed calls not to relay the claims and confirmed that there have been no reports of kidnappings in the area.

French government spokesman Benjamin Griveaux called the attacks unacceptable, adding that they showed “the absolute need to fight ‘fake news’”.

“Spreading such rumours in a highly organised and viral way on social media results in violence [and] the stigmatisation of a community,” he said, calling the process “detestable”.

In one attack on Monday night in the suburb of Bobigny, some 50 people armed with sticks and knives set upon Roma people living in a nearby slum, setting fire to their parked vans.

“Since then we’re constantly scared,” said Georghe Marcus, one of around 150 Roma from Romania, Serbia and Moldova who live in wasteland next to a canal.

“We’re not sleeping because we’re keeping guard all night.”

Roma were also chased in the Paris suburb of Clichy-sous-Bois and had to seek refuge in a supermarket to escape violence, according to Ciuciu and judicial sources who spoke on condition of anonymity.

On 16 March, a gang of around 20 young people attacked two people in a white van in the Paris suburb of Colombes, leaving both with light injuries, police said.

Many rumours appear to have been spread on Snapchat as well as on Facebook, where posts have been widely shared by people claiming their children or family members had been abducted or approached by strangers.

Police reminded social media users that under French law spreading a false rumour could be punished with fines of €45,000-€135,000 (£39,000-£115,000).

Tens of thousands of Roma have lived in France for centuries, but since the 1980s a fresh influx of around 20,000 people, mainly from Romania and Bulgaria, has led to the creation of new slums and increased tensions.

Successive French governments have sought to dismantle the slums and repatriate recently arrived Roma who, while allowed to travel freely in Europe, are not eligible to apply for jobs in France unless they meet certain qualifications.

Between 10 and 12 million Roma live in Europe, 6 million of whom are within EU borders, according to the Council of Europe.