Marseille (AFP) - France has been thrown into summer doldrums as authorities cancel fireworks and other festive events of the season because of security fears following the July 14 truck massacre in Nice.

Many traditional and cultural festivities have been either downsized or cancelled altogether, especially in the immediate area around southern Riviera coast.

Among the casualties is Nice's annual Prom'Party, when the Promenade des Anglais is usually transformed into an immense dance floor during the second half of August.

It was on the famous seafront promenade that a jihadist ploughed a 19-tonne truck into a massive crowd celebrating Bastille Day, killing 84 people and wounding more than 400 others.

Grasse, the nearby perfume capital in the hills of Provence, has decided to forgo its 70th jasmine festival, which more than 5,000 people were expected to attend this weekend.

The historic Provencal town of Avignon is turning away some 30,000 people from a fireworks show set for August 25, the anniversary of its liberation in World War II.

Defence Minister Jean-Yves Le Drian said the cancellations were warranted because of the "war situation" arising from the string of jihadist attacks to hit France in the last 18 months that together have claimed 236 lives.

"Everyone must understand that we are in this situation and that sometimes that entails constraints," he said.

The port city of Marseille cancelled its August 15 fireworks immediately after the Nice attack, and on Monday the city announced it was scrapping an August 13 air show that was to have been attended by 100,000 people.

A night of stargazing at the Marseille Observatory, set for Friday, has also been called off.

The event usually draws up to 500 people "in complete darkness, in a cul-de-sac, so that's a little scary," the planetarium's Richard Hamou told AFP.

Authorities have scrapped fireworks in southwestern Collioure, while allowing other festivities to go ahead during an annual summer event set for August 14-18, expected to draw crowds of up to 100,000.

A fireworks display set for August 15 over La Baule, a major beach in western France, has been cancelled because of the similarity between the seafront there and that of Nice.

And in the capital Paris, open-air film screenings have been moved indoors.