French police have detained 12 people after reports surfaced of individuals being stabbed with needles during the Fête de la Musique, a nationwide music celebration that drew millions to the streets over the weekend.

According to France’s Interior Ministry, at least 145 people across the country claimed they were attacked with syringes during the festival. In Paris alone, police confirmed 13 such cases.

Authorities are investigating whether the reported attacks involved needle spiking — where someone uses a syringe to inject another person, usually in the arm, leg, or buttocks. In some past cases, this method has been used to deliver substances like GHB or Rohypnol, drugs that can cause confusion, unconsciousness, or leave victims vulnerable to assault.

But so far, it’s unclear if any such substances were used in these recent incidents.

"The ministry is taking this very seriously," a spokesperson told CNN. "Toxicology tests are being done, and the investigation is ongoing."

The annual Fête de la Musique drew enormous crowds, with Paris officials calling the turnout “unprecedented.” Laurent Nuñez, head of Paris police, told French news outlet CNews that the number of people in Paris was “three to four times” higher than usual.

Concerns had been raised ahead of the event. Feminist influencers like Abrège Soeur had warned online that there were social media posts encouraging attacks on women using syringes.

“These are extremely serious incidents,” said Nuñez in an interview with CNews. He described the online calls to target women as “completely idiotic.”

Paris prosecutors confirmed that investigations have been launched after three separate victims, including a 15-year-old girl and an 18-year-old man, reported being pricked in different parts of the city. All of them later said they felt unwell, according to CNN-affiliate BFMTV.

In addition to the syringe attacks, French police arrested 371 people nationwide on Saturday night in connection with various incidents. Nearly 90 arrests were made in Paris alone, officials said.

The investigation is ongoing, and authorities continue to collect toxicology results to better understand the nature of these incidents.

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