A couple accused of trying to escape from Covid-19 quarantine in the Netherlands after testing positive for the coronavirus have been transferred to a hospital, where they were being held in isolation.

The pair, identified by Dutch authorities as a Spanish man and Portuguese woman, left the hotel where travellers who tested positive for the virus were staying after arriving at Amsterdam's Schiphol airport from South Africa.

"They have now been transferred to a hospital elsewhere in the Netherlands to ensure they are in isolation. They are now in so-called forced isolation," said Petra Faber, spokesperson for Haarlemmermeer municipality, where Schiphol is located just outside of the capital.

The couple fled the hotel on Sunday and had boarded a plane to Spain when they were detained by military police at the airport, said Mr Faber.

Speaking to Catalonia's public television channel TV3, one of the pair, Carolina Pimenta, denied they had deliberately tried to evade quarantine.

Ms Pimenta, who was travelling with her partner Andrés Sanz, said she had thought she was exempt from a five-day quarantine order because she had a negative test result and had already contracted Covid-19 in the past six months.

Ms Pimenta said she had been permitted to leave the hotel by Dutch police and health officials and cleared all airport security checks with her passport and results of a PCR test.

Just after boarding "suddenly they called me. Acting very aggressively, police treated us like criminals when their own colleagues had given us the authorisation", she was quoted as saying.

Spain's Foreign Ministry and Consulate in Amsterdam and the Portuguese Foreign Ministry did not immediately respond to requests for comment.

Dutch authorities said the couple were among 61 out of the more than 600 passengers who arrived on two flights from Johannesburg and Cape Town on Friday and tested positive for Covid-19.

The flights had arrived just before the Dutch government changed its rules on travel from southern Africa due to concerns over the newly identified Omicron coronavirus variant.

At least 14 of those infected have the Omicron variant, Dutch Health Minister Hugo de Jonge said.

Dutch authorities are also seeking to contact and test some 5,000 other passengers who have travelled from South Africa, Botswana, Eswatini, Lesotho, Mozambique, Namibia or Zimbabwe.

In the Netherlands, tougher Covid-19 measures went into effect on Sunday to curb record daily infection rates of more than 20,000 and ease pressure on hospitals.

Spain, Portugal and Switzerland latest to report variant cases

The case relates to a person who returned to Switzerland from South Africa around a week ago

Spain has said it had detected its first case of the new Omicron strain of Covid in a man who had recently arrived from South Africa.

The 51-year-old was tested when he arrived at Madrid airport on Sunday via Amsterdam and was found to be positive, the regional government of Madrid said in a statement.

"The patient has light symptoms and is undergoing quarantine," the statement added.

Portugal said it detected 13 cases of the new variant - all related to players and staff members of Lisbon soccer team Belenenses, said health authority DGS.

Meanwhile, the first probable case of the Omicron variant of Covid-19 has been detected in Switzerland, the government has said, as the country tightened its entry restrictions to check its spread.

The case relates to a person who returned to Switzerland from South Africa around a week ago, the Federal Office for Public Health said on Twitter.

Testing will clarify the situation in the coming days, it added.

Switzerland has ordered that travellers from 19 countries must present a negative test when boarding a fight to the country, and must go into quarantine for 10 days on arrival.

The list includes Australia, Denmark, Britain, Czech Republic, South Africa and Israel.

Swiss voters backed the government's pandemic response plan by a bigger than expected majority in a referendum, paving the way for the continuation of exceptional measures to stem the rising tide of Covid-19 cases.

Some 62.01% voted in favour of a law passed earlier this year to provide financial aid to people hit by the Covid-19 crisis and laying the foundation for certificates giving proof of vaccination, recovery or a negative test.

These are currently required to enter bars, restaurants and certain events.

Dutch health authorities said they had identified at least 13 cases of Omicron among 61 quarantined passengers who tested positive for coronavirus after arriving from South Africa.

Border police there announced they had arrested a couple on a plane at Schiphol Airport after they "fled" from a hotel where the passengers were being quarantined.

Despite the new threat, tens of thousands rallied in Austria to protest the government's introduction of compulsory vaccination - the first EU country to do so.

Chancellor Alexander Schallenberg said it was "a minor interference" compared to the alternative for a country with one of the lowest vaccination rates in Western Europe.

With many European nations, including Germany and France, already reintroducing restrictions to counter surges in infections, Swiss voters firmly backed a proposed Covid pass law in a referendum yesterday.

In Britain, Health Secretary Sajid Javid said new Covid rules will be enforced from Tuesday, including mandatory mask-wearing in shops and on public transport in England, and tighter restrictions on passengers arriving from abroad.

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