A French police source told AFP that the attack was deliberate.
According to the French police, a man driving a vehicle outside a high school near Toulouse "deliberately" rammed into the students, leaving two of them in a serious condition, AFP said.
The French news channel BFM reports the driver, who was immediately arrested, was known to authorities for previous crimes but was not on a list of known extremists.
A vehicle has been driven into three students near the French city of Toulouse, leaving a woman in a serious condition.
According to the police report, among the injured are Chinese students who are studying in the city.
They were taken by ambulance to Purpan Hospital.
The driver attempted to drive off but was stopped by police and arrested straight away.
According to two police officials, the suspect was born in 1989 and known to suffer from a psychiatric disorder.
Several post-18 colleges are located on the campus, including the International Institute of Trade and Development.
More than 240 people have been killed in France since early 2015 in attacks by Islamist militants or assailants inspired by the Islamic State group. La Dépêche du Midi newspaper quoted him as telling police he had heard voices telling him to harm someone.