Two people were injured by a woman in a French supermarket shouting "allahu akbar", according to local media reports.

The woman was holding a sharp object, reportedly a box cutter. The supermarket is in the town of La Seyne-sur-Mer, southern France.

Europe 1 radio reported the prosecutor of Toulon saying a customer was injured in the chest and hospitalised, while a woman at the market's cash register was also injured.

The assailant has been detained.

France is on a high terror alert following a series of attacks across Europe.

In March this year a man was shot and killed by police in the Carcassonne area of southern France after killing four people.