The powerful quake, which lasted several seconds, struck at 8:46am local time (0645 GMT), causing buildings to shake. The epicentre was between La Rochelle and the popular tourist town of Rochefort in the Charente-Maritime region.
A number of schools and other buildings in La Rochelle have been evacuated, but there were no immediate reports of casualties or significant damage, according to a statement released by local authorities.
“I was sleeping when I felt a powerful shaking. At first, I thought that it was just building work, but then I realised it was an earthquake. It didn’t last long, but it was strong enough to be frightening,” Julie, a 20-year-old resident of La Rochelle, told the regional daily Sud Ouest.
La Rochelle resident Olivier said that he “thought that a bomb or a gas canister had exploded, the walls were shaking so much I was afraid [my apartment] might collapse”.
Another woman in the nearby town of Angoulins told Sud Ouest that part of her ceiling collapsed during the quake.
An estimated population of 3.4 million people live in the affected area, according to the Paris-based real-time earthquake warning organisation EMSC.
Though smaller tremors are frequent in mainland France, strong earthquakes are rare.