French President Emmanuel Macron said his thoughts were with the victims and their families.
Eleven bodies have been found after a fire ripped through a holiday home hosting people with learning disabilities in eastern France.
Nearly 80 firefighters were sent to the blaze in La Forge after emergency services were alerted at 06:30 local time (04:30 GMT) on Wednesday.
The fire has now been extinguished, but its cause is not yet clear.
Seventeen people were evacuated from the building, with at least one person taken to hospital.
French President Emmanuel Macron said his thoughts were with the victims and their families and thanked the emergency services for responding to the “tragedy”.
Initially, emergency services confirmed nine people had died while a search for the bodies of the two remaining missing people went on.
By the afternoon deputy prosecutor for Colmar Nathalie Kielwasser confirmed the death toll had risen to 11.
The fire broke out near Wintzenheim, close to the German border and about 70km (50 miles) south of the city of Strasbourg.
The building was being used by two groups of adults from two separate charities helping people with disabilities, the local government for the Haut-Rhin region said.
In an earlier statement, it said one group was from Nancy, also in eastern France.
Four fire engines and 76 firefighters were sent to tackle the blaze. It was quickly brought under control, despite the strength of the fire, the statement added.
Drones were used to survey the wreckage of the burned-out building, while dogs were also used as part of the search effort.
Christophe Marot said those on the ground floor were able to quickly leave the building, but people upstairs could not.
French Prime Minister Élisabeth Borne visited the scene and spoke to rescue workers.
Ms Borne expressed her sadness at what she said was an appalling disaster.
In an earlier post on social media, Interior Minister Gérald Darmanin praised the bravery of firefighters who responded and warned casualties were likely, despite the fast work of the emergency services.
Photographs published in local media showed the partially wooden building in La Forge almost entirely ablaze early on Wednesday morning.
The building is an old barn converted into a three-storey holiday home. Firefighters said two-thirds of the building was on fire before they managed to bring it under control.