A man of Chechen origin who was under surveillance by French security services over suspected Islamic radicalization stabbed a teacher to death at his former high school and critically wounded three other people Friday in northern France, authorities said.

A man of Chechen origin who was under surveillance by French security services over suspected Islamic radicalization stabbed a teacher to death at his former high school and critically wounded three other people Friday in northern France, authorities said.

A man of Chechen origin who was under surveillance by French security services over suspected Islamic radicalization stabbed a teacher to death at his former high school and critically wounded three other people Friday in northern France, authorities said.