Photo: The Canadian Press

French authorities evacuated tourists from the Mont-Saint-Michel abbey and were searching houses Sunday on the famed outcropping in the English Channel for a visitor who apparently threatened to attack security services.

The exceptional and elaborate evacuation of one of France's most-visited tourist sites came after a string of sporadic attacks around France in recent years targeting police, some of them fatal.

Details of Sunday's threat were unclear, but the national gendarme service said authorities ordered the evacuation as a precaution. The suspect was still at large Sunday afternoon and an official with the gendarme service said the search was expanding to neighbouring towns.

An Associated Press reporter at the scene saw at least three police helicopters circling over the peninsula, notably famous for being isolated by high tides. The hilltop abbey, whose origins date to the 10th century, and surrounding sites attract more than 1 million visitors every year.

Thousands of tourists were affected by the evacuation, but the mood is calm. Some were taken out of their hotels, while others were blocked upon arrival.

"We wanted to go the mass at the abbey. But now we can't," said Clotilde, a 23-year-old from Paris who arrived Sunday morning.

Her friend Claire said, "We saw people walking back but we wanted to see as much as we could. So we tried to try to see it anyway but we were told to go back." The women wouldn't provide their last names.

There was contradictory information about the circumstances of the threat. An official with the national gendarme service said the man made the threat Sunday on one of the shuttles serving the site.

The head of the regional administration, Jean-Marc Sabathe, told broadcaster Francetvinfo that the man made the threat when he was trying to stage a street performance and got in an argument with a cafe worker. He said the man was caught on video surveillance cameras.

"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," Sabathe said.

The Mont's few permanent residents were being told to stay indoors, the site's administrator, Xavier Bailly, told broadcaster France-Bleu from his home.