The attacker, Radouane Lakdim, 26, a Moroccan-born French national, was a petty criminal already on the radar of French police for his links to radical Salafist networks, authorities said.

When he burst into the supermarket Friday, he shouted he was a soldier from ISIS, witnesses said, before opening fire and killing a worker and a customer. He was shot dead by police on the scene.

"Lt. Col. Arnaud Beltrame died in the service of the nation to which he had already contributed so much," French President Emmanuel Macron said in a statement. "By giving his life to end the murderous escapade of a jihadist terrorist, he died a hero."