The four women were at a train station in Marseille and were headed to Paris when they were attacked, police said, adding that authorities did not believe the incident was terror-related.
The attacker, a 41-year-old woman, was arrested at the scene, Reuters reported.
Two of the women, in their early 20s, were treated in a hospital for burns to their faces, police said.
A police spokeswoman told USA Today that the suspect did not yell any out any terror-linked threats. She said there were no immediate indications that the attack was terror-related but added officials can’t rule out terror links at such an early stage of the investigation.
In previous incidents in Marseille, a driver rammed into two bus stops last month, killing a woman, USA Today reported.
In April, French police said they thwarted an imminent “terror attack” and arrested two suspected radicals in Marseille , USA Today reported.