Eleven people were confirmed killed in eastern France on Wednesday when a fire tore through a holiday lodging being used by a group of adults with learning disabilities, officials said.

The fire at the timbered residence in the eastern town of Wintzenheim struck deep in the night while the guests were asleep, with many of those on the upper floor unable to react fast enough to save their lives.

The fire, which came at the height of the nation's summer holiday season, is the deadliest in France since a blaze at a bar in the northern city of Rouen in 2016 killed 14 people.

"Those on the ground floor are all alive and upstairs five people managed to escape. The eleven others died," regional deputy prosecutor Nathalie Kielwasser said at the scene.

The fire brigade said six bodies had been brought out and two of them had already been identified. Intensive efforts were ongoing to extract the other corpses.

"The difficulty lies in accessing the affected levels, since there is a lot of rubble, a lot of collapsed parts and the stability of the floor is very uncertain," said Philippe Hauwiller, who was leading the fire brigade search operation.

The local fire service said authorities were alerted about the blaze in Wintzenheim, just outside the city of Colmar in the eastern Alsace region, at around 6:30 am (0430 GMT).

"The fire was quickly brought under control despite the intensity of the flames," the prefecture the Haut-Rhin region said in a statement.

It said 17 people were safely evacuated, with one person hospitalised and another treated for shock.

Those staying at the centre were part of a group of adults with learning difficulties, some of whom who had come to the picturesque and hilly region from the nearby city of Nancy for the holidays.

"In Wintzenheim, the flames ravaged a lodging which accommodated people with disabilities and their companions. In the face of this tragedy, my thoughts go out to the victims, to the injured and to their loved ones," French President Emmanuel Macron wrote on Twitter, which is being rebranded as X.

Prime Minister Elisabeth Borne, who went to the scene, expressed her "sadness" over the "appalling" disaster. (AFP)