MARSEILLE (Reuters) - A woman threw acid at four female American tourists at a train station in the French city of Marseille on Sunday, an attack police said they did not believe was terrorism-related.

Two of the women, in their early twenties, were treated in hospital for burns to their faces, police said. The tourists were on their way from the southern city to Paris.

The attacker, a woman in her 40s, was arrested at the scene. Investigators have for now ruled out a terrorist motive and said they believe the attacker may be mentally disturbed, a police official said.