French authorities said they evacuated the major tourist attraction of Mont Saint-Michel after a man threatened police on Sunday.
A local bar owner heard a man uttering threats after he entered the site in the northwestern region of Normandy around 0530 GMT, district prefect Jean-Marc Sabathe told France Info radio.
"For security reasons and in order to clear up any doubt, since we don't know his aim, I've decided to evacuate the Mont," he said.
Mont Saint-Michel, which is surrounded by water at high tide, draws more than a million visitors a year to its abbey and other sites, making it France's biggest tourist attraction outside Paris.