The World Heritage site was locked down after man reportedly uttered threats against security services
France's Mont-Saint-Michel Abbey evacuated after threat
France's medieval Mont-Saint-Michel Abbey was locked down on Sunday morning while 50 police officers searched door-to-door for a man who reportedly threatened to attack security services.
The UNESCO World Heritage monasteryand monument were shut as a precaution.
A local bar owner heard a man uttering threats while at 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.
Mr Sabathe said the man was trying to stage a street performance and got in an argument with a cafe worker when the threat was uttered. Others also reported hearing threats.
"I am ordering house-by-house searches to verify if the individual is still on Mont-Saint-Michel. It's possible that the individual left the Mont with the flux of tourists," Mr Sabathe said.
The man was reportedly mixed in with the first visitors of the day.
Local authorities said the island, which draws more than two million visitors a year with its stunning medieval monastery, would be reopened to the public at 1200 GMT.
Tourists were blocked from entering the site and holidaymakers were evacuated from hotels.
"There was no panic, we were just surprised," said Denis Surfys, a holidaying journalist.
Xavier Bailly, head of the monastery which looms over the island, said police had ordered him to stay at home.
"I'm staying calm, I'm waiting for instructions from the authorities," he told AFP.
Mont Saint Michel sits about a kilometre (half a mile) off Normandy and is attached to the mainland by a bridge.
A photograph taken by a local firefighter showed the suspect as a man who appeared to be in his twenties, wearing a white t-shirt and dark trousers.
The man was also caught on video surveillance cameras. Police tracked his first movements on CCTV after the guide and several others raised the alarm, but they lost sight of him, triggering the evacuation.
While a police helicopter circled over the peninsula on Sunday, the mood remained calm.
The abbey, whose origins date to the 10th century, and surrounding sites are France's biggest tourist attraction outside Paris.
The alert comes with France still on high alert following a string of Islamic extremist attacks since 2015 that have killed more than 240 people.
Security forces have repeatedly been the target of attacks, most recently during a shooting spree and supermarket hostage-taking in the southern city of Carcassonne and nearby Trebes.
Four people were killed in the attack last month, including a police officer who offered to take the place of a woman whom attacker Radouane Lakdim was using as a human shield. Mr Lakdim, 25, had earlier shot at a group of police officers out jogging, wounding one of them.