Two pre-school children and an adult have been killed and 13 other people wounded in a knife attack at a creche in north-western Belgium.
A man who had painted his face black and white reportedly tricked his way into the nursery in Dendermonde, where he ran amok before escaping.
A suspect was arrested at a nearby shop and will appear in court later.
Parents have been asked to identify their children from photographs taken at local hospitals.
Dr Ignace Demeyer, director of a nearby hospital, told the Associated Press that 10 children had been brought in needing surgery.
The whole city is united in support for the parents who are in deep grief
"All the kids had multiple stab wounds on their legs, arms and all over their bodies," he said.
Two women - believed to be nursery workers - and another child were also hurt in the attack.
The woman who was killed was also working at the creche at the time.
Officials said the adults had been injured as they tried to put themselves between the attacker and the children.
"An act of great brutality has happened here against our weakest citizens," said Dendermonde's mayor, Buyse Piet.
"The whole city is united in support for the parents who are in deep grief."
The creche was evacuated soon after the incident and local authorities put a disaster plan in place.
Nursery staff told journalists that the attacker was not known to them.
Officials said he rang the doorbell at the Fabeltjesland nursery at 1000 local time (0900 GMT) and told staff he needed some information.
When they opened the door, he ran in and began attacking three of the infants.
"He quickly pulled out a knife and started using it on the children," said local prosecutor Christian Du Four.
"He then went up to another floor and started doing the same thing again."
The prosecutor said the man's face had been smeared with a white colouring but his eyes had been blackened.
He escaped from the scene by bicycle but was arrested at a supermarket.
Residents told the BBC that the town was stunned.
Damien Vernon, a 43-year-old from Ireland who has lived in Dendermonde for five years, said: "It's just a sad day here, we're a small town and the crime figures are low here, we're just in shock."
The creche looks after 18 children aged three and under.
Police have been showing parents digital photographs of the youngsters taken to hospital, asking them to identify their children.
The children and staff from the nursery who escaped without injury are now receiving counselling.
