Liquid containing traces of uranium leaked Tuesday at a nuclear site in southern France, and some of the solution ran into two rivers, France's nuclear safety agency said.

Authorities banned the consumption of well water in three nearby towns and the watering of crops from the two rivers. Also banned were swimming, water sports and fishing.

A spokeswoman for the nuclear safety agency, Evangelia Petit, said about 7,925 gallons of solution containing uranium spilled Tuesday at a factory at the Tricastin nuclear site. It is about 25 miles from the historic city of Avignon.

The factory handles materials and liquids contaminated by uranium, the fuel for nuclear power plants.

The liquid spilled from a reservoir that overflowed. It leaked both into the ground and into two rivers, the Gaffiere and the Lauzon, the nuclear safety agency said. It said the cause of the spill was not yet known. Local authorities said the leak happened during the washing of a tank.

The nuclear safety agency said uranium concentrations in the Gaffiere river were about 1,000 times the normal levels but were dropping rapidly.