French authorities arrested a 14-year-old on Monday after a middle school (collège) headmaster and teacher were shot with a hunting rifle, police and prosecutors said.
A third person was grazed in the shooting in the southern town of Aubagne near Marseille and the lives of the principal and teacher were not in danger, police said.
The suspected perpetrator fired several shots inside the school, before staff subdued the teenager and law enforcement intervened, France 3 television reported.
There did not appear to be a link with high school protests that have rocked France in recent weeks.
"The collège was not affected by the high school students' protest," police told AFP.
The Marseille prosecutor's office confirmed an arrest, but did not give further details.
The prime minister's office said the interior and education ministers were heading to the scene.