The blast took place at 9.10 a.m. (local time) at the bakery on Rue de Trevise in the 9th arrondissement of the French capital as firefighters were responding to reports of the leak, CNN reported.
"At this stage, we can tell the origin of the explosion is accidental, a gas leak, but we should remain prudent as an ongoing investigation will determine the causes of this," he said.
The explosion caused windows to shatter in the vicinity and glass to rattle over a larger area, while significant damage to the surrounding buildings and shops was visible on the streets, Efe news reported.
Pictures from the scene showed smashed windows and scattered debris across the street, as fire crews evacuated people from apartments above the bakery.
French Interior Minister Christophe Castaner, who visited the scene with Prime Minister Édouard Philippe and the city's Mayor Anne Hidalgo, said the situation was now under control. He wrote earlier on Twitter that the toll of victims "will be heavy".
"More than 200 Paris firefighters are engaged in emergency operations," Castaner tweeted. "My first thoughts go to the wounded and their loved ones."
The police advised the public to stay away from the area and to make space for emergency vehicles.
Jean, a young man who lives in front of the bakery, told Efe news that several windows in his house were smashed after a rumble in the streets in a scene "that looked like an earthquake".
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)