Police detained a minor suspected of killing a teacher and wounding several pupils inside a high school in Barcelona on Monday.
A regional police spokeswoman said the boy, who is aged under 14, has been taken into custody. The youth was not identified, nor whether he was a pupil at the school.
The officer said the minor used a bladed weapon to kill the male teacher but was not immediately able to confirm what type. Spanish National Television and other media outlets said the boy had a crossbow and a knife.
The officer said four pupils were slightly injured in the attack but she could not specify how.
The attack took place in a public high school in the working class neighborhood of Sant Andreu. Such schools are for pupils aged between 12 and 16.
The officer spoke on condition of anonymity in keeping with police regulations.