A police officer who swapped himself for a hostage in a supermarket siege is fighting for his life in hospital, French President Emmanuel Macron says, reports BBC News.
The gendarme, whom media named as Lt-Col Arnaud Beltrame, helped bring an end to a gunman's shooting spree that killed three in southern France.
The gunman - 25-year-old Redouane Lakdim - said he had been acting on behalf of the Islamic State group.
He was shot dead by French police after mounting three separate attacks.
Sixteen people were wonded, two seriously, in what Mr Macron called an act of "Islamist terrorism".
Lakdim is said to have been demanding the release of Salah Abdeslam, the most important surviving suspect in the November 13th 2015 attacks in Paris, which killed 130 people.
One person - believed to be Lakdim's partner - has been arrested in connection with the shootings.
The violence began on Friday morning in Carcassonne, where Lakdim hijacked a car, killing one passenger - whose body was later found hidden in a bush - and injuring the driver.
He then shot and wounded a policeman who was jogging with colleagues.
Lakdim is then believed to have driven a few kilometres to the small town of Trèbes, where he charged into the Super-U supermarket, shouting, "I am a soldier of Daesh [Islamic State]"
He killed two people - a customer and store employee - before seizing others as hostages.
Carole, who was shopping at the supermarket, said people hid in a cold room.
"A man shouted and fired several times," she told France Info radio. "I saw a cold room door, I asked people to come and take shelter."
"There were 10 of us, and we stayed an hour. There were more gunshots and we went out the emergency back door."
Interior minister Gérard Collomb told reporters that police officers had managed to get some people out but the gunman had held one woman back as a human shield.
It was at this point, he said, that the 45-year-old gendarme officer had volunteered to swap himself for her, leaving his mobile phone on a table with an open line so police could monitor the situation.
When police heard gunshots, a tactical team stormed the supermarket. The gunman was killed but Arnaud Beltrame was seriously injured.
Mr Collomb hailed the "heroism and courage" of Lt-Col Beltrame.
President Macron said he had "saved lives and honoured his colleagues and his country".