Paris: France's interior minister says that four people have been killed, including two firefighters, and 47 have been injured in the blast at a bakery that was apparently caused by a gas leak in central Paris.
Christophe Castaner told reporters at the scene "unfortunately the human toll is particularly serious."
He said 10 people are in critical condition and 37 others less seriously injured.
He 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.
Paris Mayor Anne Hidalgo, who was also at the scene, extended a "message of affection and solidarity" to the victims.
Around 200 firefighters were mobilised to battle the fire that broke out after the blast and evacuate victims and residents in the area, Interior Minister Christophe Castaner told reporters at the scene.
The explosion came with the city on edge during the latest "yellow vest" anti-government demonstrations, which have often degenerated into violence and vandalism in Paris and other cities in recent weeks.
"It happened when there were people in the street, and firefighters inside," Castaner said.
Around 100 police officers blocked off several streets in the area, home to restaurants and tourist attractions including the Musee Grevin wax museum and the popular Rue des Martyrs.
Police also closed off streets in front of the Garnier Opera house as emergency services landed two helicopters in front of the historic building to evacuate victims. The explosion occurred shortly after 9:00 am (0800 GMT) in building that housed a bakery as well as a restaurant on the ground floor in the Ninth Arrondissement.
The shockwave was felt as far as four blocks away, Commander Eric Moulin of the Paris fire service said, adding that rescuers were still searching for other victims.
"I was sleeping and woke up by the blast wave," Claire Sallavuard, who lives on the Rue de Trevise where the explosion occurred, said.
"All the windows in the apartment exploded, doors were blown off their hinges, I had to walk on the door to leave the room, all the kids were panicking, they couldn't get out of their room," she said. "Firefighters advised us to leave but the elevator shaft had been blown out, there was no railing, nothing, and there was too much smoke," she added.
Rescuers eventually used a ladder to evacuate the family, who lived on the first floor. Firefighters had been responding to an alert of a gas leak at the site when the explosion occurred, Paris prosector Remy Heitz said at the scene.