At least three people have been confirmed dead, while dozens have been injured following an explosion and fire at a bakery, caused by an apparent gas leak, according to French and Spanish officials.

Two of the three fatalities were firefighters, according to French Interior Minister Christophe Castaner, who warned on Saturday afternoon of "a heavy toll" following the explosion.

Spain's foreign ministry office also confirmed that a female Spanish national died in the incident.

"I profoundly regret the death of three people in an explosion in central Paris, among them one Spanish citizen," Spanish Foreign Minister Josep Borrell wrote on Twitter.

A police spokeswoman said firefighters arrived at the scene of the explosion on Saturday morning at the bakery on Rue Trevise in the 9th arrondissement of north-central Paris.

Earlier, officials said four people were killed and at least 37 people injured, including 10 in critical condition. The number of fatalities was lowered from four to two, before it was revised to three.

French television showed emergency vehicles surrounding the area.

Images shared on social media showed the area around the adjacent Rue De Montyon covered in debris with a fire raging in at least one building.

Destruction for blocks after an explosion on rue de trévise pic.twitter.com/GsrLqyasQA — Emily Molli (@MomesMolli) January 12, 2019

"I was sleeping and woke up by the blast wave," Claire Sallavuard, who lives on the Rue de Trevise, told the AFP news agency.

"All the windows in the apartment exploded, doors were blown off their hinges, I had to walk on the door to leave the room, all the kids were panicking, they couldn't get out of their room," she said.

Rescuers eventually used a ladder to evacuate the family, who lived on the first floor.

Police sources said firefighters had already been responding to an alert of a gas leak at the site when the explosion occurred.

The explosion took place amid heavy security in Paris and around France in the wake of yellow vest protests expected later on Saturday.