France's top security official says a heroic officer who swapped himself for a hostage during an attack on a supermarket has died of his injuries.
Interior Minister Gerard Collomb wrote in a tweet early on Saturday that Colonel Arnaud Beltrame had "died for his country".
Col Beltrame offered himself up unarmed to the 25-year-old attacker in exchange for a female hostage.
He managed to surreptitiously leave his phone on so that police outside could hear what was going on inside the supermarket.
Officials said once they heard shots inside the market they decided to storm it, killing the gunman.
Le lieutenant-colonel Arnaud Beltrame nous a quittés.
Mort pour la patrie.
Jamais la France n’oubliera son héroïsme, sa bravoure, son sacrifice.March 24, 2018
Col Beltrame was grievously injured, and his death raises the toll from the attack to four.
The Islamic State group claimed responsibility for the attack, the deadliest since Emmanuel Macron became president last May.