While many wondered whether the phenomenon was linked to some kind of military exercise and others panicked that planes were on fire, the fire balls are believed to have been caused by a meteorite shower.
Social networks lit up at around 6.20pm on Wednesday after hundreds of people caught sight of a fire ball passing through the sky.
"You're never going to believe me but I saw a meteorite, something on fire falling from the sky! "F**king hell I 'm in shock," said one eyewitness.
Vous n'allez jamais me croire j'ai vu une météorite, un truc en feu tomber du ciel! Qui c'est désagrégé ! BORDEL DE MERDE JE SUIS CHOQUÉ— CASIPERY (@Qcastelas) February 17, 2016
The regional newspaper Dauphiné Libéré said hundreds of eye-witnesses had contacted them from right across southern France.
Readers described seeing a “green ball with a trail” or a “white ball that exploded followed by a long trail of fire.”
One resident in the Alps told Le Parisien newspaper the meteorite “passed pretty low and horizontally and was a big ball of green fire.”
y'a eu chez pas quoi c'etais un truck énorme on aurait dit une météorite ou un avions en flamme à st raph ! Chez moi pic.twitter.com/9EMkZfqOyN— Nico … 萨科 (@nico83np) February 17, 2016
The newspaper reported that three meteorites had made “impact” with the ground in the Isere département, without causing any damage.
The exact locations where the meteorites hit the ground have not been identified, but one was near Vercors Autrans, another near Saint-Vincent-de-Mercuze and the last near the town of Gières.
Police in the Savoie region said they had received numerous calls to report the sighting.
To try to calm people's imaginations police took to Twitter and let the public know that the phenomenon they had seen was probably a meteorite shower.
Last week a man in India was believed to have picked up the unfortunate title of being the first man in the world ever to have been killed by a meteorite. Although that theory has since been rubbished by Nasa.
NASA says a meteorite probably didn't hit India https://t.co/yEfrOQWBsL— TIME.com (@TIME) February 10, 2016