TREBES, France, March 24, 2018 (AP) — A French police officer who offered himself up to an Islamic extremist gunman in exchange for a hostage has died, raising the death toll in the attack in southern France to four. He was honored Saturday as a national hero of "exceptional courage and selflessness." Lt. Col. Arnaud Beltrame, 44, was among the first officers to respond to the attack Friday on the supermarket in the southern French town of Trebes. Beltrame, who joined the elite police special forces in 2003 and served in Iraq in 2005, had organized a training session in the Aude region in December for just such a hostage situation. At the time, he armed his officers with paintball guns, according to the Depeche du Midi newspaper. "We want to be as close to real conditions as possible," he said then. But when he went inside the supermarket, he gave up his own weapon and volunteered himself in exchange for a female hostage. Unbeknownst to the Morocco-born hostage-taker, he left his cellphone on so police outside could hear what was happening in the store. They stormed the building when they heard gunshots, officials said. Beltrame was fatally wounded.