Four people are in a critical condition after a huge explosion in central Paris caused several buildings to set on fire and prompted an evacuation in the Left Bank.
Two people are feared to be trapped in the rubble from the accident at a private school known as the Paris American Academy, which has injured 24 people - some seriously.
More than 270 firefighters attempted to extinguish the fire at the height of the blaze which sent a plume of black smoke across the French capital.
One woman named only as Raphaëlle, who lives opposite the collapsed building, told BFMTV: “I heard an explosion, a noise more powerful than any I have heard in my life.”
Her windows were open at the time and she said debris and shattered glass were in her house.
Speculation suggests the explosion was caused by a gas leak in the fifth arrondissement.
A student at the private school said he was in a building about 100 metres away when the explosion rocked the area.
Achille, told BFM television: "I was sitting on the windowsill, and we moved two meters away from the window, carried by a small blast (from the explosion) and huge fear.
"We came down (from the building) and saw the flames. The police gave us great support and we evacuated quickly."
Paris Police spokeswoman Loubna Atta said it was too early to determine the source of the fire and could not confirm reports it was caused by a gas explosion.
Police chief Laurent Nunez added the firefighters managed to stop the fire form spreading to two nearby buildings which were also evacuated.
Florence Berthout, mayor of the arrondissement, said people were in an "absolute emergency" condition.
Describing pieces of glass falling from buildings, she added: "The explosion was extremely violent."
French Interior Minister Gerald Darmanin confirmed the fire on Rue Saint-Jacques in Paris’ fifth arrondissement, close to the Jardin Du Luxembourg and Sorbonne University.
The neighbourhood was cordoned off and scores of emergency workers filled the area.
“I saw a ball of fire 20 or 30 metres high", one witness told CNews.
While public health researcher Loïc Josseran said there was "an extremely violent noise which made the windows vibrate strongly."
French news channel BFM TV showed fire services trying to hose down a building and journalist Olivier Galzi told the channel that he had seen the facade of a nearby building "completely collapse".
Paris police urged people to avoid the area and said they were making checks on the incident.
