Fire fighters struggle to save lives of victims in the gas explosion.
Several victims are extracted by helicopter after a blast in a bakery overturns cars and blasts out the fronts of several shops.
An explosion thought to be caused by a gas leak in central Paris has left two firefighters dead and dozens injured.
The Paris prosecutors’ office says 10 people are in critical condition and 37 others were less seriously injured.
It was previously reported that four people were killed, including two firefighters.
France’s Prefecture de Police says the blast occurred in a bakery in Rue de Trevise, in the 9th arrondissement, north-central Paris.
Several buildings in the surrounding area were damaged and pictures of the scene show a large amount of debris strewn in the street, about a mile north of the Notre-Dame cathedral.
Windows were blasted out of neighboring shops and apartments and cars were overturned. Broken glass covers the pavements nearby.
Commander Eric Moulin of the Paris fire service said: “Twelve people are seriously injured, including three firefighters, and 24 others have more minor injuries.
“Among the 12, two firefighters and three civilians are in life-threatening condition,” he added.
It comes as Paris is braced for a ninth weekend of anti-Emmanuel Macron protests by the Gilets Jaunes.
Sky’s Alistair Bunkall, who is on the scene, said: “The Pompiers and the Gendarmerie are here in large numbers. It’s pretty chaotic at the moment, in term of the cordon and what went on.
Reporter – A woman is evacuated by firefighters from an apartment after an explosion in a bakery
“A bakery might suggest it is a gas explosion but when you have Paris on high alert here, because of the Gilets Jaunes protests – police are out in the thousands – it really adds to the complexity of what is already a highly charged policing operation.
“Lots of reports of casualties but whether the reports of fatalities are accurate, we don’t know yet.”
A tourist who was in the street at the time with a group of others said: “In the middle of nothing, I heard this big explosion.
“A lot of pressure came out of it, a lot of black smoke and glass. I just had time to get down and cover myself and my head. I felt a lot of things fall on me.
Reporters – An injured man is evacuated on a stretcher by firefighters
“I was in panic. Fortunately, I know my hotel well, so I ran. I don’t know what I stepped on. I just ran.
“I’ve spoken to my clients and a few of them got injured in the head. They were bleeding.”
Interior Minister Christophe Castaner said: “The toll appears to be high, and severe.”
Police have closed off streets the Opera theatre in order to land two helicopters in the street, apparently to evacuate victims.