The violent winds, heavy rains and lightning struck France late Tuesday and lingered Wednesday, forcing authorities to issue an alert for several areas.

Campers in wooded sites were particularly vulnerable. Three of those killed had been on vacation in the Landes region on the southwestern Atlantic coast.

Police said two Dutch tourists -- a 39-year-old man and a 10-year-old girl -- and a two-year-old French girl died after being hit by falling trees late Tuesday at separate campsites southwest of Bordeaux.

Authorities said they were also searching for an adult who was seen disappearing while on a lake in the area.

The other two deaths Tuesday resulted from a 17-year-old boy losing control of his moped during a ferocious hail storm and hitting an oncoming vehicle in the Pyrenees-Atlantique region near Spain, and a man who died of a heart attack at a campsite near Saumur, much farther north in the Loire Valley region.

Around 70 people were injured in the storms, 10 of them seriously, according to the emergency services.

Sarkozy was to visit the Landes region Thursday afternoon to inspect a campsite where one of the fatalities occurred, and to speak with local officials.

Several French newspapers gave the storms front-page treatment.

One of them, France-Soir, noted that France's national weather service Meteo France had issued several storm warnings but that campers had apparently ignored the danger.

The newspaper confirmed that a bulletin had gone out Tuesday morning, but it quoted an unnamed official in the Maine-et-Loire region as saying: "But we have storm alerts every two days!"

Meteo France told the paper it has taken extra efforts to inform authorities of dangerous weather since December 1999, when storms of extraordinary force ripped across France, killing 92 people.

Forecasts were now for sunny weather across virtually all of France to Saturday, with a heat wave that was broken by the storms gradually returning.

TERRA.WIRE