Belgium is mourning the deaths of 28 people – 22 of them children – in a coach crash in Switzerland.
The coach, carrying 52 people back to Belgium following a skiing trip, struck a wall in a tunnel on Tuesday.
Relatives of the victims have flown to Switzerland – with many unsure about the fate of their children.
Belgian PM Elio Di Rupo called it “a black day for all of Belgium”. King Albert said his thoughts “go out to the victims and their families”.
The Belgian foreign ministry said most of the children were aged around 12, and the bus was one of three hired by a Christian group. The other two reached Belgium safely.
The children had spent a week skiing in Val d’Anniviers in the Swiss Alps.
Those on board the bus that crashed were from the Stekske primary school in Lommel, near the Dutch border, and from St Lambertus in Heverlee, near Leuven, with the numbers roughly even.
Ten of the children involved are Dutch, the Dutch foreign ministry said, with all but one of them living in Belgium.
The injured have been taken to hospitals in Sion, Bern and Lausanne. Belgian media say many are in a critical condition and the death toll could rise.
A helpline for families has been set up.
Speaking to the press Wednesday morning, prosecutor Olivier Elsig told the affected families he would do everything possible to find out what had happened, according to the police statement. He said the bus was new or nearly new, and was fitted with seat belts.
The speed limit in the tunnel was 100 kilometers per hour (62 mph), the statement said.
Jean-Pierre Deslarzes, medical chief of the Canton Valais rescue organization, is quoted as saying the accident had upset and shocked even the toughest of the rescue personnel.
There has never been an accident involving such a large number of children, he said, according to the police statement. Some 200 rescuers had worked for eight hours to help the injured, Deslarzes said.
“It was a difficult night for all the people engaged on the scene,” Moulin said, expressing his condolences to families.
He said rescuers had gotten quickly to the crash site but nothing could be done for the many children who were killed.
“To end a ski trip like that. … There’s no words to describe what happened there,” he said.
Belgium has made available two military planes to take parents to see their injured children and to bring them back, Vandeweyer said.
The European Parliament also fell silent to mark the tragedy. Martin Schulz, the assembly’s president, paid tribute to the rescue workers and expressed his condolences to the families.