At least 24 people have been injured after an explosion at a building in Paris’ Left Bank, police said.
The blast ignited a fire that sent smoke soaring over monuments in the French capital and prompted the evacuation of surrounding buildings.
Officials from the district attributed the blast and blaze to a gas leak.
The facade of a building in the fifth arrondissement, or district, collapsed and emergency services were working to determine whether anyone was still inside, police added.
The explosion happened near the historic Val-de-Grâce military hospital.
Paris police chief Laurent Nunez said the building where the explosion occurred was a private school, the Paris American Academy, which was founded in 1965 and offers teaching in fashion design, interior design, fine arts and creative writing.
The fire was contained. Some 270 firefighters were involved in putting out the flames and 70 emergency vehicles were at the scene.
A Paris police official told the Associated Press that 24 people were injured, including four in a critical condition and 20 with less severe injuries. The official said the injuries were sustained mainly when people were blown off their feet by the blast.
Florence Berthout, mayor of the district, said “the explosion was extremely violent”, describing pieces of glass still falling from buildings.
The Paris prosecutor said an investigation was opened into aggravated involuntary injury and the probe would examine whether the explosion stemmed from a suspected violation of safety rules.
Paris prosecutor Laure Beccuau said investigators would seek to “determine whether or not there was a failure to respect a rule or individual imprudence that led to the explosion”.
Mr Nunez said firefighters prevented the blaze from igniting two neighbouring buildings that were “seriously destabilised” by the explosion and evacuated. The explosion blew out several windows in the area, witnesses and the police chief said.
Smoke was no longer visibly rising from the building by Wednesday evening. Sirens still wailed as ambulances passed through the neighbourhood, but residents were starting to move freely again on the street, Rue Saint-Jacques, which has been cordoned off earlier.
A student at the private school said he was in a building about 100 metres from the explosion.
“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,” the student, Achille, told BFM television.
“We came down [from the building] and saw the flames. The police gave us great support and we evacuated quickly.” -AP