Three teenagers were wounded in a stabbing on a shopping street in The Hague, Dutch police say.
Police launched a manhunt after the attack, which took place on a busy shopping street near the city's historic centre. The area was cordoned off and dozens of police and ambulances were on the scene.
All the victims were minors and were receiving treatment in hospital, police said in a statement, adding that their families have been informed.
"We are at this moment searching for a suspect, no-one has been arrested yet," police spokeswoman Marije Kuiper told reporters.
Images and videos on social media showed dozens of Black Friday shoppers running away from the scene.
National broadcaster NOS said the attack could not immediately be attributed to terrorism.
"At this moment there is no indication of a terrorist motive," the broadcaster said, quoting "varied sources".
Ms Kuiper said police did not yet have a description of the suspect, but she said an initial police statement that he was a man in his 40s of North African descent had been wrong.
"At this moment all scenarios are still open," she said.
Police have urged the public to contact them if they witnessed the attack.
Officials have also requested that anyone with images or footage of the attack send it to police.
Another stabbing earlier on the same day in London, UK, ended with police shooting the suspect, whose attack left two members of the public dead and three people taken to hospital.
- Reuters / BBC