A teen swordsman, armed with two swords, is holding four children and their nursery assistant hostage at Charles Fourier pre-school in Besancon in Eastern France.
The 17-year-old hostage taker, who is suffering from a personality disorder, originally took 20 children hostage but has since released 16 of the children.
The mayor of Besancon, Jean-Louis Fousseret, told French radio: “For the moment I am optimistic.”
He also explained that the armed man had made some demands when he went into the nursery “declaring that he wanted something”, however Mr Fousseret did not go into any details on exactly what the youth had demanded.
All other classes in the school were evacuated from the building when the man stormed in, and are now in safety.
A spokesman for the mayor, Jean-Marc Magda, told BFM-TV that the families of the children are being offered psychological and medical assistance.
He also explained that the 17-year-old suffers from a personality disorder and that they are in contact with the doctor of the hostage taker.
A special police force from Strasbourg has joined the local police to help cope with the delicate situation.
The school is located in the Planoise area in western Besancon, which is a neighbourhood with many housing projects and a large population of immigrants.