France has issued a terror alert after a man opened fire in a school in Grasse, France.

The man, who was carrying "several weapons" shot the headmaster at the Alexis de Tocqueville school in the small town.

According to the French publication Interieur, police have confirmed that one man has been arrested, but it is thought that another is on the run.

Subsequently, a terror alert has been issued and residents of the town have been advised to stay inside.