Business owners and opposition politicians in Italy rebelled on Wednesday against the latest restrictions imposed to combat a spike in coronavirus cases, after days of occasionally violent protests.

Scores of chefs and restaurateurs joined a rally in central Rome at lunchtime, kicking off protests in 24 cities organised by a business federation against rules forcing restaurants, bars, gyms and other businesses to close their doors at 6pm.

Far-right and nationalist politicians ramped up their attacks on Prime Minister Giuseppe Conte, accusing him of sacrificing the economy for measures that will not save Italy from the virus.

As he struggled to quell the anger late on Tuesday, Conte announced a package of tax cuts and support for the most affected businesses worth more than €5 billion.

However, warnings were growing that the health system was starting to struggle after the country registered 21,994 cases on Tuesday - the highest 24-hour count since the start of the pandemic.

Protests in several cities have turned violent in recent days as football hooligans, far-right activists and others have brought trouble to otherwise peaceful demonstrations.

Wednesday's Rome protest, held in front of the Pantheon close to the Senate, drew politicians of all stripes keen to get on side with the burgeoning movement - even as its leaders insisted it was politically neutral.

"There is no health benefit from the closure of bars and restaurants, only economic disadvantage," said opposition leader Matteo Salvini from the protest sidelines, a day after he threatened to mobilise officials belonging to his far-right League party against the new restrictions.

And regional politicians began to amend the national regulations brought in just two days ago, with Sicily announcing it intended to extend opening hours for bars and restaurants.

"What is the point of preventing us from leading an almost normal life until the possible arrival of lockdown," asked Sicily President Nello Musumeci, saying local officials had the power to push back closing time until 10pm if they chose.

While those calling for lighter restrictions sharpened their criticism, health experts were urging more severe curbs - particularly in hard-hit northern regions.

"The hospitals in Milan are collapsing, there is no more room for patients," said Maurizio Viecca, head of cardiology at Sacco di Milano hospital, a day after a government health adviser had called for Milan's Lombardy region to be locked down.

"Go on like this, you risk dying in an ambulance or at home, as happened in the spring."