Italy will tighten restrictions for arrivals from the rest of the EU from Thursday, requiring coronavirus tests of everyone and a five-day quarantine for those who are not vaccinated.

Previously, EU arrivals had to show proof of vaccination, recent recovery or a negative test.

The decree signed by Health Minister Roberto Speranza late on Tuesday "provides for the obligation of a negative test on departure for all arrivals from European Union countries", a spokesperson said.

"For the unvaccinated, in addition to the negative test, a five-day quarantine is planned."

Unvaccinated people arriving from outside the bloc must already quarantine, and tests are required of those with jabs.

The new measures, valid from December 16 to January 31, come as Europe battles a fresh wave of coronavirus infections as winter settles in and the new Omicron variant takes hold.

Early data suggests two vaccine doses may not offer as much protection against Omicron and is more transmissible than the Delta variant, which currently accounts for the bulk of the world's coronavirus cases.

Italy was the first EU country to experience a major outbreak of COVID-19 in early 2020. 

In recent months, it has sought to control infections through the use of health pass showing proof of vaccination, recent recovery or a negative test for everything from going to work to eating in restaurants.

European Commission spokesman Christian Wigand said they had not yet been notified of Italy's new temporary restrictions, despite what he said was the obligation of member states to inform the Commission 48 hours in advance.

"Additional restrictions on certificate holders are only possible where this may be necessary and proportionate to safeguard public health in response to the COVID-19 pandemic," Wigand said. 

"It remains crucial to ensure the proportionality of any measures taken".

More than 20,000 new cases were reported in Italy on Tuesday, and another 120 deaths.