TREBES, France (AP) - The Latest on the extremist attack in southern France (all times local):

10:05 a.m.

The Paris prosecutors' office says that police have detained a 17-year-old in connection with the investigation into the Islamic extremist attack that killed four people, including a police officer, in southern France.

The unidentified young man was arrested overnight over alleged criminal association in relation with a terrorist enterprise. He is a friend of the gunman, identified by prosecutors as Morocco-born Redouane Lakdim, who was killed in a shootout Friday at a supermarket in Trebes where he took hostages.

Paris prosecutor Francois Molins said Friday that another person, a woman close to Lakdim, was taken into custody on the same grounds. Molins didn't identify her.

Paris counterterrorism investigators took over the probe into the attack in Trebes and nearby Carcassonne.

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9:20 a.m.

The mother of a French police officer who was killed after he swapped himself for a hostage during an Islamic extremist attack on a supermarket says that she wasn't surprised by her son's courage.

Col. Arnaud Beltrame had offered himself up unarmed to the 25-year-old attacker in exchange for a female hostage in the southern town of Trebes. The attacker shot him and Beltrame later died of his injures.

Beltrame's mother told RTL radio Friday night before the announcement of his death that "I'm not surprised. I knew it had to be him. He has always been like that. It's someone, since he was born, who gives everything for his homeland."

Asked if she was proud of him, she said he would have told her "'I'm doing my job mom, that's all.'"

She said to "defend the homeland" was his "reason for living." RTL didn't give her name.

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6:35 a.m.

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 Saturday that Col. Arnaud Beltrame had "died for his country."

Beltrame offered himself up unarmed to the 25-year-old attacker in exchange for a female hostage. He managed to surreptitiously leave his cellphone 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.

Beltrame was grievously injured, and his death raises the toll from the attack to four.

The Islamic State-linked Aamaq news agency said the attacker was responding to the group's calls to target countries in the U.S.-led coalition. The attack was the deadliest since Emmanuel Macron became president last May.

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