A woman and a man were killed and a teenage girl critically injured on Thursday after a gunman opened fire at a house and a prominent medical school in the Dutch port city of Rotterdam, an unusual outburst of violence in the city that the police chief called a “black day”.

The Rotterdam police chief, Fred Westerbeke, said at a news conference on Thursday evening that a 39-year-old woman and a 46-year-old male teacher at Erasmus University Medical Centre had been killed.

The woman’s 14-year-old daughter was also wounded and was in critical condition at a hospital, he said. None of the victims were immediately identified. The Rotterdam police arrested a 32-year-old Erasmus student as a suspect. He was carrying a weapon and wearing a bulletproof vest, the authorities said. He was also not identified.

Much remained unclear, including a motive and the relationship between the victims and the suspect.

The authorities said they had received an initial report of gunfire at 2:25pm local time on Thursday. The gunman started a fire at the home, then moved to the medical school, where he shot the teacher in class, the police said. The gunman then made his way through other parts of the hospital and started a fire there, the police said.

Images on social media showed people, some wearing medical gowns, rushing from the building.

In their initial alert, the police warned on the social media platform X, formerly Twitter, that a suspect had been seen wearing combat clothes, carrying a backpack and headphones, and using a handgun. Erasmus Medical Center also alerted people not to go to the facility.

The suspect was arrested as he came out of a hospital building, the police said.

The authorities said they had informed “family and relatives” of the shooting victims, and that there was no indication a second shooter was involved.

Gun violence is unusual in the Netherlands, but in 2019 the country was shaken by a shooting on a tram in the city of Utrecht that left at least three people dead and seven others wounded.

This year, Rotterdam has been rocked by small explosions at homes and businesses blamed on rival gangs.

New York Times News Service