FREE now and never miss the top politics stories again. SUBSCRIBE Invalid email Sign up fornow and never miss the top politics stories again. We will use your email address only for sending you newsletters. Please see our Privacy Notice for details of your data protection rights.

Two women suffered facial injuries and two other travellers, all in their twenties, were left nursing burns following the attack. One has a possible eye injury, according to the prosecutor's office. It is understood the tourists were in Gare Saint-Charles station in Marseille just after 11am this morning when the 41-year-old female attacker suffering from a mental health illness sprayed them with hydrochloric acid. Hydrochloric acid, if strongly concentrated, can cause severe burns. It can also be dangerous if it comes into contact with a person's eyes and can cause blindness.

GETTY•WIKIPEDIA Two women suffered facial injuries after the acid attack

However the students, who are all hoping to continue their studies in France, say they have forgiven their attacker. Two of the woman had asked for prayers for their assailant in Facebook posts late Sunday. One of the women, Michelle Krug, said she was one of two who got hit in the eye with "a weak solution of hydrochloric acid." And she asked friends to "please consider thinking about/praying for our attacker" so she can receive help, adding: "Mental illness is not a choice and should not be villainized."

GETTY Hydrochloric acid, if strongly concentrated, can cause severe burns

All four of those involved in the incident were thought to be American women, who were travelling as a party between Paris and Marseille. The acid was thought to be in a spray canister sold in DIY shops for cleaning purposes. Local media say the acid hit two girls in the face leaving them with facial burns, while two others are in shock. A female suspect was arrested by police. According to La Provence, she was also suffering from burns.

GOOGLE The tourists were in Gare Saint-Charles station in Marseille