A 20-year-old knifeman fatally stabbed a teacher in an attack at a school in the northern France city of Arras that President Emmanuel Macron condemned as "barbaric Islamic terrorism". Two other people were seriously wounded and fighting for their lives, Macron said after visiting the school. "The teacher who was killed stepped in and undoubtedly saved a lot of lives himself," Macron said after paying his respects to the dead teacher, whose body still lay under a cover and surrounded by a pool of blood. Saying the school would reopen on Saturday, he added: "Our choice is made not to give in…