At least 20 people have been killed, 10 of them children, in a devastating fire at a hotel in central Paris, a fire service spokesman said.
The cause of the blaze is still unclear
At least 12 of the injured were in a serious condition after the blaze which began at about 0200 (2400 GMT), gutting the modest, one-star Paris-Opera hotel.
Many victims were African immigrant families waiting to be re-housed. Fifty people are said to have been injured.
Some of the guests leapt out of the hotel's windows to escape the flames.
President Jacques Chirac - a former mayor of Paris - said it was one of the city's "most painful catastrophes".
The fire started on the first floor and swept through the six-storey-building via the stairwell, fire service spokesman Laurent Vibert said.
Most of the victims were trapped on the upper floors.
Seventy-six people were staying in the hotel on Rue de Provence in Paris's ninth arrondissement, near the city's upmarket department store district.
It is still unclear how the fire started.
The BBC's Alasdair Sandford in Paris says there are bound to be questions over safety procedures and why so many people were unable to escape.
The Paris-Opera is one of many privately-owned hotels used by the social services as temporary housing for families who need urgent help, a spokesman for the Paris city council told the BBC News website.
These hotels are also used by budget travellers.
Those injured in the fire included people from France, the US, Portugal, Senegal, Tunisia, Ukraine and Ivory Coast, police said.
Fire services said the hotel had a single entrance - adding that a separate fire exit is not mandatory for older buildings.
Chakib San, who lives in an adjacent building, told the Associated Press news agency that he was awakened by cries of "Fire! Fire!".
He said he saw three people jump from the building, including a woman and a child.
"They were on the ground. They weren't moving," he said.
"Everyone was screaming. There were bodies in the road."
Dozens of fire engines, 250 firefighters and 10 ambulances took part in the rescue effort. It took about 90 minutes to put out all the flames.
An emergency hospital and a makeshift morgue were set up in the nearby Galeries Lafayette department store.
Many of the injured were suffering from burns and smoke inhalation.
A counselling centre has also been set up for victims, many of whom are in shock.
Interior Minister Dominique de Villepin has visited the scene, as did Paris Mayor Bertrand Delanoe.