Six people including five children were killed and 31 injured Monday when a train ploughed into a packed school bus on a level crossing in the French Alps, local officials said.
The crash occurred at around 2:00 pm (1200 GMT) in the town of Mesinges, when a regional train linking nearby Evian and Thonon-les-Bains struck a bus carrying 50 children and six adults.
"Five children were killed. Four passengers on the bus were seriously injured -- it is not known if they are children or adults -- and 27 children were slightly injured," said an official at the local prefecture.
The prefecture later said a sixth person had died but could not say if the victim was a child or an adult.
President Nicolas Sarkozy paid tribute to the children during a speech on education at the Elysee palace, calling on the audience to spare "a thought for the victims of this very serious accident" in the Alps.
"All of us are thinking of the children, the adults, the victims whoever they are," said the president. "We can only hope there will be as few victims as possible."
The local prefecture earlier gave a toll of five dead and six seriously injured among the children on the bus, which was travelling between the local towns of Margencel and Yvoire.
A spokeswoman for the French state rail company SNCF said several train passengers were also lightly injured.
Local authorities set up a crisis cell to provide on-site medical assistance and councilling for victims and their relatives, the prefecture said.
Interior Minister Michele Alliot-Marie and Transport Minister Dominique Bussereau immediately travelled to the scene.
Darcos met with the families of the victims to express his "saddest condolences," the education ministry said.
The minister called for full light to be shed on the circumstances of the crash, after meeting the head of the children's school.
According to initial SNCF data, the level crossing was functioning properly at the time, the spokeswoman said.
"Records from the control screens at the level crossing, which was remotely monitored, show that everything appears to have worked normally up until the accident," she said.
Further evidence was being gathered at the crash scene, she said.
A French truck driver was killed and 35 rail passengers injured in December when a TGV high-speed train linking Paris and Geneva collided with a truck on a level-crossing in eastern France.
And in October 2006, six people were killed when a passenger train and a goods train collided head-on in northeast France.