A number of people were killed in the Dutch city of Rotterdam on Thursday after a man went on a shooting spree, causing multiple deaths including a teenager.

Iran PressEurope: Dutch police said a gunman opened fire in a classroom at a university hospital campus in Rotterdam and a nearby house.

The shooter, who acted alone, was apprehended and the motive behind the shooting remains unknown.

The man first burst into a house and opened fire, killing a 39-year-old woman and seriously injuring her 14-year-old daughter, police chief Fred Westerbeke told reporters. The girl later died of her injuries.

Videos posted online showed police instructing students, some wearing medical gowns, to run outside as heavily armed arrest teams arrived at the scene. One video showed a man in handcuffs wearing what appeared to be camouflage pants.

"This is a very dark day," Dutch caretaker Minister of Justice and Security Dilan Yesilgöz was quoted as saying by the newspaper de Telegraaf.