At least 29 injured in massive blast in central Paris

At least 29 people were injured Wednesday, including four in serious condition, in a massive explosion that rocked central Paris, according to media reports.

Army troops, police, 230 firefighters and other emergency services, rushed to the scene in the Fifth Arrondissement, according to broadcaster BFMTV, which said at least two people remain under the rubble of collapsed buildings.

Paris Deputy Mayor Edouard Civel said the accident may have been caused by a gas explosion and told residents to stay away from the area.

The Paris Prosecutor's Office said, however, the cause of the explosion remains unknown and an investigation is underway to determine details.

Police said a fire that erupted after the blast has been contained and rescue teams are searching the rubble for survivors.