A teacher has been killed and two other people critically injured in a stabbing at a school in Arras, northern France. The suspected attacker, who has been arrested, was on a watchlist of people known to be a security risk in connection with radical Islamism. Local media reported that he was a former pupil at the Gambetta-Carnot school. Police said the man was born in 2003 in Russia’s mainly Muslim southern region of Chechnya. He arrived in France in 2008 with his family. Other sources told French media the 20-year-old had been flagged as a possible security risk only 11 days ago and had been under surveillance by the country’s intelligence services including phone taps. He was reportedly stopped by police on Thursday but released. France’s anti-terrorism prosecution office said it would start an investigation, as the French president, Emmanuel Macron, arrived at the scene mid-afternoon. On Friday evening the teacher who was killed was named as Dominique Bernard, 57. Reports said that he was a French teacher who was married to another teacher who taught English. He had three children. Earlier Macron said: “The teacher who was killed intervened first. He undoubtedly saved many lives. His seriously injured colleague and the staff who were also seriously injured showed the same courage. But so did the headteacher and many others in that moment. “I am here to show the nation’s support. To say that we are united and that we are standing firm … The choice has been made not to give in to terror, not to allow anything to divide us.” The attack happened at about 11am. A second teacher, reported to be a sports teacher, and a school security guard were in hospital with critical injuries, according to the local prefect. A video on social media filmed by students showed a man in a grey jacket carrying a knife and attacking people in the school courtyard. One of the victims tried to keep him at a distance with a chair. Several French media outlets reported that the suspect’s elder brother was currently in prison having been sentenced to five years for “associating with terrorist criminals” and 18 months for “justifying terrorism” in connection with a foiled attack, earlier this year. A second brother, younger than the suspect, was also arrested after the killing on Friday. The Arras attack came almost exactly three years after Samuel Paty, a 47-year-old history and geography teacher, was killed in an attack by an 18-year-old Chechen refugee outside his school in the Paris suburb of Conflans-Sainte-Honorine, on 16 October 2020. Martin Doussau, a philosophy teacher at the school in Arras, said he had come face-to-face with the suspect, who had just attacked the third victim. He said the man had asked him “quite aggressively” several times if he was a history teacher. It was at that moment, he said, he realised the attack was linked to Paty’s murder. “He chased me and kept [asking] if I was a history teacher. It was when he asked this I realised it was an external problem, not something linked to a settling of scores in the lycée,” Doussau told BFMTV. “[The attacker] then turned towards someone he had already injured and it was then the police arrived. They didn’t shoot him but neutralised him with a Taser. It all happened in about 10 minutes, from the moment he entered, attacked a colleague and the police arriving.” Doussau added: “I don’t think [the attacker] was looking [for] someone in particular, but he was looking for a history teacher. Our thoughts are with our assassinated colleague. We’re shocked by this situation.” The Gambetta-Carnot school is made up of two establishments: a college for pupils aged 11-15, and a lycée for those aged 15-18. Sliman Hamzi of the Alliance Police union said officers were on the scene quickly, though nothing could be done to save the teacher who had his carotid artery cut and died almost immediately in the school courtyard. Hamzi said he arrived as the suspected attacker was being taken away by police. Fabien Dufay, a sports teacher at the school, said he was returning with a group of students when he received a call telling him of the attack and advising him to remain outside. “We thought it was an exercise to start with, but then we were told a colleague had died. It’s shocking.” Local police said the situation had been contained and no longer posed a danger to the public. Students and teachers were confined to the school premises for two hours before they were allowed to leave. A vice-president of the lower house of parliament, Naïma Moutchou, said the national assembly “expresses its solidarity and thoughts for the victims, their families and the educational community as we learn that a teacher has been killed and several others have been injured”. France has been hit by a series of attacks by Islamist extremists since 2015. Paty’s killing led to a wave of rallies and renewed debate about the influence of radical Islam.