A fire broke out on Friday on the seventh floor of the "Maison de la radio" ("Radio house"), a vast circular building in Paris housing several media operations.
Firefighters said the blaze started on the seventh floor, which is currently under reconstruction, and employees were quickly evacuated from the building.
Two radio stations, France Info and France Inter, stopped transmission due to the blaze but restarted shortly afterwards.
A tweet from France Bleu radio says: "Fire at the Maison de la Radio. Explosions heard. Firefighter not yet arrived."
Two radio stations, France Info and France Inter, stopped transmission due to the blaze. There were no immediate reports of injuries, according to a police source.
In a tweet the director of France Info radio said, "The France Info team is safe. We'll be back on the air as soon as possible."
Toutes les équipes de @franceinfo sont en sécurité. Nous reprenons l'antenne dès que possible— Laurent Guimier (@laurentguimier) October 31, 2014
"I heard a big noise, like an explosion," said Faouzi Zenassi, head of a team of construction workers on the site.
Firefighters put the explosions down to the windows blowing out under the force of the inferno.
"We don't yet know how bad the damage is, but it seems considerable," French President Francois Hollande told reporters at a joint news conference with Turkish President Recep Tayyip Erdogan.
The fire is an "extremely traumatic event" in central Paris, Hollande said, adding that it was a "symbolic" building.
"I am watching this very carefully," he added.
The 50-year-old building is an iconic structure in the posh 16th district of Paris that has been undergoing significant renovation since 2009.
The renovation work is the largest project on an occupied building in the whole country and is due to finish in 2016, at a cost of €350 million ($437 million).
Journalists inside the building said that no alarm had sounded. "For a quarter of an hour, we were saying 'what shall we do'?" said Isabelle Labeyrie, from France Info radio station.
"While we were waiting for the order to evacuate, we took pictures," she added.