The Mayor of Reims Adeline Hazan has told the French news agency BFM TV that at least "two people were killed" in the accident at a four storey block of flats in the city.
Initial reports on local French media suggest the explosion may have been caused by a gas leak.
More top news
How are the regions commemorated the soldiers killed in the Battle of the Somme?
Mosha had part of her leg blown off by a landmine on the Myanmar-Thailand border when she was seven months old.
With UK trials of driverless cars underway across the country, worries about the vehicles have been raised following a crash in Florida.