Two people have been arrested after Emmanuel Macron appeared to be slapped in the face by a bystander during a visit to southern France on Tuesday.
Footage circulating on social media showed the incident in Tain-l'Hermitage, around 90 kilometres south of Lyon.
Macron, who was on a visit to a Drôme hospitality school, was struck in the face while shaking hands with a member of the public.
The prefecture confirmed the news and the two arrests in a short statement issued after the incident, which took place at about 1.15pm.
"The president got back into his car after visiting a high school and came out because onlookers were calling him," authorities said. "He went to meet them and that was where the incident happened.
"The man who tried to slap the president, and another individual, are currently being held by the Tain-L'Hermitage gendarmerie."
Politicians united in outrage over Macron 'slap'
French politicians from across the political spectrum were quick to condemn the alleged attack on Tuesday.
"Politics can in no way be violence, verbal aggression, and even less physical aggression," French prime minister Jean Castex told MPs.
Xavier Bertrand, an ex-Republican Party member and president of the Hauts-de-France region, called the gesture "unacceptable" on Twitter, adding: "No political disagreement will ever justify violence."
National Rally (formerly National Front) leader Marine le Pen also weighed in on the incident, telling reporters on Tuesday: "I am the first opponent of Emmanuel Macron but he is the President of the Republic.
"As such, we can fight him politically, but we cannot afford to have to the slightest gesture, the slightest violence. This behaviour is unacceptable and deeply deplorable in a democracy."
Jean-Luc Mélenchon, leader of the La France Insoumise group, tweeted: "This time you begin to understand that the violent take action? I stand in solidarity with the President."
Laetitia Avia, the serving MP for the 8th district of Paris, said on Twitter: "To attack Emmanuel Macron, the President of the Republic, is to attack France. This violence is intolerable and must be condemned, no 'buts', by all: today and tomorrow."
La République en Marche MP Sacha Houlié also told parliament on Tuesday that the incident "calls for condemnation, and awareness by everyone of the way we behave."
Former president Francois Hollande also reacted to the incident, writing on Twitter: "To attack the President of the Republic is to deal an unbearable and intolerable blow to our institutions. Faced with this unspeakable gesture, the whole nation must show solidarity with the head of state."