Police in the French city of Metz detained a teenager armed with a knife who threatened to kill a teacher, BFMTV reported on Friday.
The 15-year-old pupil was arrested at 10:20 am at the Philippe de Vigneulles college shortly after he had called the emergency services saying "that he wanted to kill a teacher".
The teenager had a 30-cm blade on him, the TV channel added.
The broadcaster said, citing the police, that neither terrorism nor a religious motive has been considered in this incident. According to initial data, the police learnt that tensions already existed and that the parents had been summoned to the school because the pupil had done inadequate work.