Four children have been killed after a train struck a cargo bike being ridden by a woman who went over a level crossing.
The electrically powered bicycle, widely used by Dutch parents to transport their children, was taking them from a pre-school centre to school when the accident occurred.
It happened in the southern town of Oss, about 62 miles southeast of Amsterdam.
There were several witnesses, including other school-age children, police said.
Two people were critically injured – a child and the woman operating the vehicle.
“We have informed the families involved of this terrible news,” police said in a statement.
“We are investigating how this could have happened.”
ProRail, the company responsible for rail infrastructure in the Netherlands, said the cause of the collision is under investigation.
The company’s chief executive, Pier Eringa, said initial investigations suggested that the barriers at the crossing were working correctly at the time of the accident.
“There are no words to describe this,” Mr Eringa said.
“Our thoughts are with the families who lost their children in the terrible accident in Oss,” a visibly upset Dutch Queen Maxima told reporters during a visit to the northern region of Friesland.
Oss mayor Wobine Buijs-Glaudemans offered condolences to “the families, the school, the day care centre and everybody else involved.”