Four passengers flown back to Britain from quarantined cruise ship Diamond Princess have tested positive for coronavirus.

They were among 30 repatriated Britons and two Irish citizens starting a 14-day quarantine at Arrowe Park Hospital in Wirral.

The group landed back in the UK from Tokyo on Saturday on a government repatriation flight.

The four UK nationals caught the virus on the Diamond Princess in Japan, England’s chief medical officer said.

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This brought the total number of cases in the UK to 13.

They have now been transferred to specialist NHS infection centres.

The Department of Health said a “full infectious disease risk assessment” was carried out before the special flight from Japan, adding that no-one who boarded the flight had displayed any symptoms of the virus.

Any more passengers who test positive will immediately be taken into specialist NHS care, the department said.

It added that “appropriate arrangements” are in place at Arrowe Park, including strict separation of passengers from staff and from each other.

Meanwhile, Austria was reported to be considering imposing border controls as Italy sought to control the largest outbreak of coronavirus in Europe with more than 150 cases and three deaths.

Quarantine restrictions were imposed for two week on about 50,000 people in two regions in northern Italy close to Milan and Venice.

The annual Venice carnival was cut short by two days due to concerns over the spread of coronavirus.

The Foreign Office said in updated travel advice: “The government of Italy has introduced extraordinary measures that allow regions to implement civil protection measures in response to coronavirus.

“This includes the isolation of ten small towns in Lombardy and one in Veneto.

“The regions of Lombardy, Veneto, Friuli Venezia Giulia, Piemonte and Emilia Romagna have implemented measures including the suspension of public or private events, the suspension of schools and higher education and the suspension on the opening of museums and cultural institutions for seven days.

“If you are already in the regions affected you should follow instructions of local authorities.

The FCO also advised against all but essential travel to the cities of Daegu and Cheongdo as South Korea raised its coronavirus alert to the “highest level”.