Paris police look at gas leak as possible cause of explosion and fire that injured 24

A strong explosion rocked a building in Paris' Left Bank on Wednesday, injuring at least 24 people, igniting a fire that sent smoke soaring over the French capital's monuments and prompting an evacuation of other properties, authorities said. Police were investigating suspicions that a gas leak caused the blast.

The facade of the building in the 5th arrondissement collapsed, and officials said rescuers were searching for two people who might be trapped inside. The explosion happened near the historic Val de Grace military hospital, in one of the most upscale neighborhoods of the French capital.

Some 270 firefighters were involved in putting out the flames and 70 emergency vehicles were sent to the scene. The fire was contained but not yet extinguished Wednesday evening, as Paris bars and restaurants celebrated the summer solstice with a citywide annual music festival.

Sirens wailed as ambulances passed through the neighborhood and police initially cordoned off the street, rue Saint-Jacques. By evening, smoke had stopped pouring out of the building where the explosion occurred.

"It is possible that overnight we will find bodies or people alive," Interior Minister Gerald Darmanin said from the scene.

District Mayor Florence Berthout said on French TV channel BFM that firefighters were searching for two people believed to have been inside the building at the time of the blast. "The explosion was extremely violent," she said, describing pieces of glass still falling from buildings.

Paris police chief Laurent Nunez said the building housed a private school, the Paris American Academy. The school was founded in 1965 and offers teaching in fashion design, interior design, fine arts and creative writing.

A Paris police...