Arras (France) (AFP) - France was on high alert on Saturday, after an attacker stabbed a teacher to death in what the president called an act of “Islamist terror,” with troops deployed and major attractions including the Louvre museum and Palace of Versailles evacuating visitors.

Friday’s attack took place in the northeastern town of Arras, home to large Jewish and Muslim populations.

A man in his twenties killed French teacher Dominique Bernard and severely wounded three others at the school he used to attend.

On Saturday, amid fears the conflict between Israel and Hamas could lead to violence in foreign capitals, France announced it would deploy up to 7,000 soldiers under the highest warning level.

Police arrested the suspected perpetrator of Friday’s attack, Mohammed Moguchkov, who had cried the Arabic phrase “Allahu akbar!” (God is greatest).

He was among 11 people being held in custody on Saturday, a police source told AFP, including his 17-year-old brother and several other family members.

In Paris, the famous Louvre museum evacuated visitors and closed following a “security” threat.

A spokeswoman for the Louvre, the largest museum in the world, told AFP it had “received a written message stating that there was a risk to the museum and its visitors”.

The Palace of Versailles, also a major tourist attraction just outside the capital, was evacuated due to a bomb threat made anonymously online, police sources told AFP.

The deployment of the soldiers from Operation Sentinelle will be completed by Monday evening, according to the Elysee presidential palace.

Sentinelle is a French military operation involving the deployment of soldiers, police and gendarmes set up in the aftermath of January 2015 attacks to protect parts of the country deemed sensitive from terrorism.

“This school was struck by the barbarity of Islamist terrorism,” President Emmanuel Macron said after visiting the school, adding the victim had “probably saved many lives” with his courage in blocking the attacker.

Macron said another attempted attack outside Paris had been foiled by security forces.

According to the interior ministry, the president was referring to the arrest of a “radicalised” man arrested leaving a prayer hall in the Yvelines region bordering Paris for carrying a prohibited weapon.

Interior Minister Gerald Darmanin later said there was “probably a link between what’s happening in the Middle East and this incident” in Arras.

France upped its alert level to maximum following a crunch security meeting Friday, the prime minister’s office told AFP.

The national anti-terrorist prosecutor announced it has opened an investigation.

French authorities said Moguchkov was Russian, born in the predominantly Muslim North Caucasus republic of Ingushetia.

He was already on a French national register as a potential security threat, a police source told AFP, and under electronic and physical surveillance by France’s domestic intelligence agency, the DGSI.

- ‘Terrorism has struck’ -

Bernard was stabbed in the throat and chest. Among those wounded were a school security guard who was stabbed multiple times and is fighting for his life, and a teacher in a less serious condition.

A cleaner was also hurt, according to anti-terror prosecutor Jean-Francois Ricard.

No pupils at the school were hurt.

School pupils throughout France will observe a minute’s silence on Monday.

The attack came almost three years to the day after the October 16, 2020 beheading of teacher Samuel Paty near his school in a Paris suburb.

At an event in Paris commemorating his death, Prime Minister Elisabeth Borne said, “I want to tell all teachers: we will be there to ensure your safety.”

“We will not give in to violence. We will face it and fight it,” she added.

- Panic in school -

Martin Dousseau, a philosophy teacher who witnessed the attack, described a moment of panic, when schoolchildren found themselves face-to-face with the armed man.

“He attacked canteen staff. I wanted to go down to intervene, he turned to me, chased me and asked me if I was a history and geography teacher,” Dousseau said.

“We barricaded ourselves in, then the police arrived and immobilised him.”

On Saturday, the school was open for students to talk about the previous day’s tragedy.

“I’m feeling sadness and anger,” said Victoire, a 17-year-old final year student taught by Bernard.

“He was always there for us, he was really an extraordinary person”.

France has suffered several attacks by Islamist extremists since 2015 including the suicide and gun attacks in November 2015, claimed by the Islamic State group, on targets in Paris where 130 people were killed.

There has been a relative lull in recent years, though officials have warned that the threat remains.

- Stepped-up protection -

Macron said in an address to the nation on Thursday that 582 religious and cultural facilities in France were receiving stepped-up police protection after the attack by Hamas on Israel.

Speaking in Arras, he reaffirmed his message from that address for the French to “stand shoulder to shoulder” and “stay united”.

Darmanin on Thursday banned pro-Palestinian demonstrations in France until further notice, as they “are likely to generate disturbances to public order”.

In defiance of his order, several hundred people gathered in Paris and other French cities on Thursday shouting pro-Palestinian and anti-Israeli slogans, AFP correspondents said.

Police in Paris used tear gas to disperse the protesters, and said they had arrested 10 out of around 3,000 people present.