Hundreds of rescuers backed by helicopters evacuated about 1,600 people as a precaution on Thursday in southern France’s Gard, Ardeche and Drome regions, where heavy rain caused flash flooding and transformed rivers and streams into torrents earlier that day.
Most of the evacuees were campers, the interior ministry said in a statement, as camping sites were particularly affected by the swollen rivers.
After a hot spell, flash flooding in the Gard region turned the Ceze and Ardeche Rivers into churning waterways that quickly spilled out of their banks.
Ten people suffering from hypothermia and minor injuries have been taken to hospital, according to regional police spokesperson Jerome Tallaron.
Several parts of central and southeast France are still on flood alert.
Power was cut for tens of thousands of homes in the area on Thursday, according to media reports, which added that numerous roads have remained inaccessible.
Authorities have urged vigilance and warned that the flooding would take time to recede.
Elderly man missing
A 75-year-old German man, who was helping supervise children at a campsite in southeast France, was reported missing by police on Thursday after being swept away by floodwaters.
He was accompanying a group of some 100 German children who were evacuated from a campsite in Saint-Julien-de-Peyrolas in the Gard region. The young campers have been reported safe.
Trapped by a muddy, fast-flowing torrent after the Ardeche River burst its banks, he sought shelter inside his caravan, but the vehicle was swept away. It was later found "empty and in pieces" near the river, police said.
He was the only person unaccounted for after a rescue operation at three campsites in the area.
Divers were taking part in the search for the missing man, an AFP journalist at the scene said.