At least two American women students were injured after an acid attack at a railway station in Marseille in southern France on Sunday, The New York Times reported, quoting local police. Two others who were accompanying them seemed to have escaped injury.

The suspected attacker, a 41-year-old woman, was arrested and is reported to have a history of mental illness. However, she did not appear to be connected with any militant groups. “For now, nothing suggests that this was a terrorist attack,” a spokeswoman for the Marseille police was quoted as saying.

The students, all in their early 20s, were in front of the Saint-Charles railway station when the attacker threw hydrochloric acid on them shortly before 11 am, the police said. The two women who seemed to have escaped injury were in a state of shock, the police said. All four were treated at a hospital and have now been released.

The four women were students of Boston College, enrolled in study-abroad programmes, the college said in a statement.