A third person was grazed in the shooting in the southern town of Aubagne, near Marseille, per police. Authorities said the headmaster and teacher were not in critical condition.
French authorities arrested a 14-year-old on Monday after a middle school headmaster and teacher were shot with a hunting rifle, police and prosecutors said.
A third person was grazed in the shooting at Joseph Lakanal school in the southern town of Aubagne, near Marseille, police said.
Authorities said the headmaster and teacher were not in critical condition.
"The suspect, for reasons as yet unknown, fired at the headteacher, who was hit by a shower of pellets in the thighs and lower back," Jacques Witkowski, prefect of the wider Bouches-du-Rhone region, said.
He then shot at another teacher, who was hit in the thigh, before a member of staff disarmed him, Witkowski went on.
He added that the suspect was "not known for any history of delinquency or radicalisation."
There did not appear to be a link with high school protests that have rocked France in recent weeks.
"The middle school was not affected by the high school students' protest," police told the AFP news agency.
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.
This is a developing story, and our journalists are working on further updates.