A teacher was killed Friday and several people injured in a knife attack at a public school in Arras, northern France, according to CNN affiliate BFMTV.

A worker at the school is in critical condition after receiving several stab wounds and a second teacher was wounded less seriously, BFMTV reported.

The attack occurred in the Gambetta High School at around 11 a.m. local time (5 a.m. ET) Friday, BFMTV said.

According to a post on X from French Interior Minister Gerald Darmanin, the attacker was detained by police.

According to BFMTV, the suspect is a 20-year-old man of Chechen origins who cried "Allahu Akbar" during the attack. His brother was also reportedly detained.

French President Emmanuel Macron is traveling to the public school where the attack occurred, according to the Elysee Palace.

French police have posted on X asking people to avoid the area and avoid spreading misinformation online about the incident.