An explosion that caused a fire at a bakery in central Paris on Saturday killed at least three people and injured 47, French authorities said. At least 10 people are believed to be in critical condition after the blast, which blew out windows and overturned cars.

Two of those killed were firefighters, according to police. Later, the Spanish Foreign Ministry said a woman from Spain who was on holiday in Paris also died as a result of the explosion.

Authorities said the massive explosion, likely caused by a gas leak, gutted the ground floor of the building. The blast happened at around 9 a.m. local time (0800 UTC).

"We still need to determine the circumstances and cause of the explosion, but at this stage we can say it is clearly an accident, presumably a gas leak," Paris prosecutor Remy Heitz told reporters, adding that officials did not suspect foul play.

The firefighters had been responding to a gas leak alert at the site when the explosion occurred, Heitz said. "First there was a gas leak and the firefighters arrived, then there was an explosion that caused the fire."

Police closed off streets as emergency services landed two helicopters in the street, apparently to evacuate victims.

Interior Minister Christophe Castaner told reporters at the scene that "the situation is now under control." 

Castaner said more than 200 firefighters were attending the scene at the bakery on Rue Trevise in the 9th arrondissement of north-central Paris.

Firefighters worked to extinguish the blaze and evacuate some people from the building using ladders, while emergency workers treated some of the injured.

Police have urged commuters to avoid the area. 

On Saturday afternoon, French Interior Minister Christophe Castaner said that the situation was "under control."

law,es/rc (AFP, AP, Reuters)