French authorities have issued a terror warning after a gunman opened fire in a technical school in the south of France injuring several people.

The attack occurred Thursday afternoon at the Alexis de Tocqueville military school located in the French riviera town of Grasse in the south of the country. So far authorities say they have detained one 17-year-old “European type” suspect, who may have been a student, but have not said whether or not they acted alone.

According to reports in French media the arrested individual was carrying a rifle, pistol, revolver, and grenades. Three are injured, including 16-year-old Julien, 17-year-old Akram, and the headmaster of the school.

The government has activated the terror warning system, locking down all local schools. The action suggests French authorities are treating the incident as a terrorist attack. Police SWAT teams are on the scene and are currently investigating the area, the Le Figaro reports.

#SAIP déclenché sur comune de #Grasse suite aux tirs survenus au Lycée de Tocqueville pic.twitter.com/Kl943644Q9 — Paul Danielzik (@Pdanielzik) March 16, 2017

According to Christian Estrosi, president of the Provence-Alpes-Côte d’Azur region, one of the people injured at the school was the headmaster.

Je me rends au lycée Tocqueville de #grasse suite à des coups de feu. Le proviseur serait blessé — Christian Estrosi (@cestrosi) March 16, 2017

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