A large explosion caused by a gas leak tore through central Paris on Saturday morning, killing three people and injuring scores.

Two of the dead were firefighters who were responding to the gas leak in a bakery on the Rue de Trevise in the 9th district of the French capital. A Spanish woman was the third person confirmed dead. The blast occured around 9 a.m. local time (3 a.m. EST).

Some 47 people were injured in the blast, 10 of them seriously; among the seriously injured was a firefighter. Some of the injured were evacuated using helicopters.

French Interior Minister Christophe Castaner said "a dramatic explosion" occured when the firefighters were investigating the leak, adding one of the firemen was buried under debris for several hours.

The ground floor of the building was gutted and windows in adjacent buildings were blown out. Police evacuated the area. Pictures from Twitter showed buildings on fire and firefighters trying to extinguish the flames amid the debris scattered by the blast. Several nearby buildings including a theater were damaged; parked cars were overturned by the explosion.

Paris and other French cities have been the site of the "yellow vest" protests in recent weeks, and the authorities were bracing for another day of violence and vandalism Saturday. But the blast was not linked to the protests, or terrorism.

"At this stage we can say (the blast) is clearly an accident," Paris prosecutor Remi Heitz told reporters. But he said investigations were just beginning to ascertain the cause of the leak. Paris has suffered a string of attacks from Islamists in recent years.