Millionaires and Hollywood stars visiting Italy have been put on notice that they no longer own the beach after a group of celebrities led by Flavio Briatore, co-owner of QPR football club, were pelted with wet sand and showered with water as they tried to land dinghies on a crowded Sardinian beach.

Already victims of shrinking spending power and sky-rocketing rates for renting deckchairs, Italians have descended on their beaches this August in a surly mood, and the sight of the Briatore-led flotilla as it carved a swath through alarmed swimmers was enough to spark a near riot on Friday at the packed Capriccioli beach.

The Italian newspaper La Stampa seized on the episode as the start of a fightback against celebrities flaunting their wealth on the country's top beaches, stating: "From north to south, the rebellion against those who show off their money and power is growing."

The authorities also appear to be clamping down. Last week, Michael Douglas and Catherine Zeta-Jones came ashore from their yacht at the Italian resort of Santa Margherita Ligure, the same spot where locals were kept awake in June by thumping music from Wayne Rooney's rented yacht. After failing to notify the coastguard of the names of all the members of the landing group, the captain of Douglas's yacht was fined £1,600 under immigration and anti-terrorism legislation.

Hostilities erupted in Sardinia when Briatore, the manager of the Renault formula one team, came ashore from a yacht to inaugurate his new restaurant, which opened on Friday just behind the beach and is close to his opulent disco Billionaire, a bastion of the super-rich.

Briatore and his new bride, the TV showgirl Elisabetta Gregoraci, were met with grumbling from sunbathers as they hopped off the first dinghy, rising to whistles and shouts when the Italian newsreader Emilio Fede climbed off the second, while "terrorised children wailed between the waves", reported La Stampa.

Yelling "Shame! Louts! Go home!", a mob formed to greet the third dinghy, attempting to push it back out to sea, as mothers filled their children's buckets with water to sling at the passengers and wet sand bombs were hurled.

The episode marked a tough homecoming for Briatore, who has enjoyed an extended honeymoon since his star-studded Rome wedding in June. "We are nice people and we get rewarded like this," Corriere della Sera quoted Briatore as saying after he returned to the beach to find out why his guests were being drenched. "I will close down everything," he warned. "I pay taxes, this is my right."

With his new restaurant designed as a lunch stop for passing mega-yachts, Briatore may be wondering how Arab princes and Russian oligarchs will react to lobbed sand. But a Billionaire spokesman hinted that all may be in hand: "This year we are opening the restaurant, but from next year we will manage the beach as well."