Regional authorities said 455 people were cleared in the operation, ordered over the “worrying” sanitary situation at the encampment, where rats had been spotted and where some migrants had caught scabies.
Nantes, a riverside city in Brittany home to 300,000 people, has seen asylum applications jump 28 percent in a year, bucking a trend among most other big French regional cities.
The migrants evicted from the city-centre camp were sent to a public hall where officials were examining their cases.
Regional authorities said they would shelter “the most vulnerable people” and asylum seekers “as much as possible”, but warned that their facilities were “saturated”.
Officials had said last week that they had found only 100 spaces in emergency shelters throughout the region.
“It means at least 300 people are going to sleep in the street tonight, without tents,” said Francois Prochasson, a member of a local group which helps migrants.
“They’re just going to go somewhere else, to another park, and nothing will have been fixed,” he said.
Regional authorities said migrants who “cannot claim asylum or legal residency, or who have claimed asylum in another European Union member state, will be asked to leave the country”.
President Emmanuel Macron’s government is pushing through parliament a tough new immigration law which would speed up the asylum process and accelerate deportations.
France received a record 100,000 asylum applications last year, though the overall numbers entering Europe via dangerous Mediterranean crossings have fallen sharply from their peak in 2015.
