A police officer has also reportedly been shot

A French police union official says the suspect in a hostage siege on a supermarket has been shot dead.

Three people have been killed - as well as the gunman - and about a dozen wounded in the incident in the south of the country.

A policeman has also been shot.

It's believed police launched a raid on the shop after a man, who reportedly claimed allegiance to the Islamic State group, took hostages earlier.

The man was reportedly seen entering the Super U supermarket in town of Trebes at around 11.15am.

French Interior Minister Gérard Collomb confirmed the shooter was shot dead in a tweet, before deleting it.

 Anti-terror prosecutors have taken over the investigation.

French media reported that the policeman was shot in the town of Carcassonne, while a gunman fired shots during a hostage-taking Friday morning at a supermarket in the town of Trebes 15 minutes' away.