France's interior minister said three people were killed, including two firefighters, and 47 were injured in a powerful blast at a bakery in central Paris that is believed to have been caused by a gas leak.
A blast ripped through the small Rue de Trevise in the 9th arrondissement of the French capital at around 9am local time, overturning cars, blowing out windows and starting a large fire.
Speaking at the scene of the explosion, Interior Minister Christophe Castaner said that "unfortunately the human toll is particularly serious". He said 10 people were in critical condition and 37 others had been less seriously injured.
President Emmanuel Macron said the firefighters were heroes and paid homage to the courage of rescuers who saved the life of one firefighter who was buried under the rubble for two-and-a-half hours.
Among the dead was a Spanish woman who was holidaying in Paris with her husband, the Spanish foreign ministry said.
Paris Mayor Anne Hidalgo, who was also at the scene, extended a "message of affection and solidarity" to the victims.
Parisian police warned the public to "avoid the area and allow the passage of the emergency vehicles".
Throughout the morning, firefighters worked to extinguish the blaze and used ladders to clear people from the building while other emergency workers treated some of the injured at the scene.
The cause of the blast appeared to be an accidental gas leak, said Paris prosecutor Remy Heitz. Firefighters were already at the scene before the explosion to investigate the cause of the leak, he said.
The situation was "under control" by the time Mr Castaner visited the site, which he described as shocking. About 200 firefighters and police were involved in the operation to contain the situation, he said.
Earlier, witnesses described an overwhelmingly loud blast and then hearing screams from people trapped in nearby buildings.
"I heard one big explosion and then a lot of pressure came at me [and] a lot of black smoke and glass," Pedro Goncalves, an employee at the Hotel Mercure opposite the bakery, told the Associated Press. "And I had just enough time to get down and cover myself and protect my head."
Images shared online showed the bakery as a blackened shell, with broken glass and charred debris littering the street outside. Many shops and buildings on the street and those immediately surrounding the explosion on Rue de Trevise had shattered windows.
The capital was preparing for weekly protests by the "yellow vest" movement, which is campaigning against Mr Macron's economic policies.