Four American women were attacked with acid in Marseille's main train station in France on Sunday, the city's prosecutor's office has just announced.
All four victims were hospitalized, two having suffered shock and one having a potential eye injury.
There was no immediate information on where the US tourists are from.
French reports say the incident is not being treated as terror-related and witnesses said no slogans were shouted during the attack. Paris prosecutor Francois Molins told reporters the two suspects "were getting ready to carry out an imminent, violent action" on French territory.
A 41-year-old woman was arrested in connection with the attack in the port city in southern France, the AP reported.