French President Emmanuel Macron announced Saturday that 7,000 soldiers would be mobilized after the country activated its highest alert level following the stabbing death of a teacher in an apparent Islamist attack.

According to Euronews, French authorities have opened anti-terror investigations after 18-year-old Mohammed Mogouchkov attacked three people, killing one teacher, in a high school in Arras on Friday morning. Police say the attacker shouted “Allahu Akbar,” an Arabic phrase which means “God is great.”

During his recent visit to the school following the attack, Macron urged people to remain “united” in what he described as “the barbarity of Islamist terrorism.”

These comments follow Macron’s recent statements regarding the conflict in Israel. In a Thursday address, Macron said:

As of Saturday, I asked the government to strengthen our measures to protect schools, places of worship and culture. 582 of them saw their security increased. 10,000 police officers and gendarmes are mobilized. Our armies are engaged as part of Operation Sentinel. Prosecutors have been instructed to pursue anti-Semitic acts and glorification of terrorism with the greatest severity. Demonstrations which could give rise to excesses will be prohibited. We are also extremely vigilant in the face of expressions of hatred on social networks and the terrorist threat.

This stance has been upheld by the French Interior Minister Gérald Darminin, who announced a ban on pro-Palestinian rallies Thursday. After protests ensued anyway, French police employed tear gas and water cannons to disperse the outlawed demonstrations, with at least 20 arrests made.