A 15-year-old student has been arrested on suspicion of killing a fellow pupil at a school in western Germany, police have said.
Dortmund police said paramedics were called on Tuesday morning to the school in the nearby town of Luenen but were unable to resuscitate the 14-year-old German victim.
The suspect, who has German and Kazakh citizenship, was arrested shortly after the incident. Police said their investigations into the circumstances of the killing are ongoing but said rumours on social media that the attack was directed at a person who was not the victim could not be confirmed.
Neither boy was identified.
Relatives of the victim, students and teachers at the school were getting psychological counselling, police said.