U.S. President Donald Trump has denounced Friday’s attack in France that claimed four lives, including that of a police officer who exchanged himself for a hostage the gunman was holding captive in a supermarket in the southwestern town of Trebes.

“Our thoughts and prayers are with the victims of the horrible attack in France yesterday, and we grieve the nation’s loss,” the president posted on Twitter.

He added, “We also condemn the violent actions of the attacker and anyone who would provide him support. We are with you @EmmanuelMacron!”

Earlier Saturday, France’s interior minister said Lieutenant-Colonel Arnaud Beltrame, the police officer who exchanged himself for the hostage, had died. 

“He died for his country. France will never forget his heroism,” Interior Minister Gerard Collomb wrote Saturday on his Twitter account. 

Authorities said two people had been arrested in connection with the shootings, including a woman who was reported to have been close to the assailant.  

The gunman shot three people to death Friday during a burst of violence.

Car hijacking

First, he hijacked a car near Carcassonne, in southern France, Friday morning, killing the passenger and wounding the driver. He then drove off in the car and shot into a group of police officers who had been jogging, wounding one of them.

Next, in Trebes, near Carcassonne, he walked into the Super U supermarket where he opened fire, killing two people. He held several hostages in the supermarket, where Beltrame volunteered to trade himself for a hostage.

The gunman agreed and Beltrame kept an open line on his phone so his fellow officers could hear what was going on. When the officers heard more gunshots, they stormed the market, killing the gunman. Beltrame had been wounded.

​Terrorism

After Macron said evidence suggested the gunman’s actions were considered terrorism, the Islamic State militant group’s propaganda arm claimed responsibility.

“The person who carried out the attack in Trebes in southern France is a soldier of the Islamic State and he carried out the operation in response to a call to target the states” of the anti-IS global coalition, the Amaq agency stated on the messaging app Telegram.

Collomb said Friday, however, that police had not considered 26-year-old suspect Redouane Lakdim, who was born in Morocco and lived in Carcassonne, a terrorist threat.

“He was known by the police for petty crimes. We had monitored him and did not think he had been radicalized,” Collomb said. He added, “He was already under surveillance when he suddenly decided to act.”

The Paris prosecutor’s office said counterterrorism authorities had assumed control of the investigation.

France has been on high alert after being hit with a series of Islamic State extremist attacks since 2015 that have killed more than 200 people.