PARIS -- French rescuers backed by helicopters evacuated about 750 people, including many children and tourists, from campsites in southern France after torrential rain swelled rivers in the Gard region Thursday. One person was reported missing.

After a hot spell, flash flooding hit the northern part of the Gard region, turning the Ceze and L'Ardeche rivers into churning waterways that quickly spilled out of their banks. Nearby regions -- all part of the verdant and mountainous Cevennes -- also were hit with flooding.

A top regional official, Thierry Dousset, told French news channel BFM TV that the some 750 people evacuated came from five campsites.

The missing man, a 70-year-old German citizen, was a monitor at one of the campsites who was feared to have been swept away by flood waters along with his van, BFM-TV reported.

A search was underway for him. However, Dousset, the top aide of the Gard administration, said no one knew for certain yet that the man was in his van at the time.

The Gard administration also said four German children were hospitalized Thursday for hypothermia in Bagnols-sur-Ceze, a town on the Ceze River. They were among 10 people hospitalized with minor injuries, the Gard Gendarmerie said on its Facebook page.

The mayor of Bagnols, Jean-Yves Chapelet, told BFM TV many Dutch tourists were among the 350 campers evacuated in the town.

Authorities also said 119 children in nearby Saint-Julien-de-Peyrolas were sent to an emergency shelter.

Hundreds of firefighters, many sent in from other regions, helped in the evacuations, using helicopters to spot camp sites and occasionally to perform rescues.

Numerous roads in the area remained cut off as night fell.