Israel will shut its borders to visitors on Sunday in response to growing concerns over the new Omicron coronavirus variant.
The travel restriction is part of a series of new measures, which also permit the security service to track mobile phones.
The ban on foreigners came less than a month after Israel opened its doors to vaccinated tourists for the first time since the start of the Covid-19 pandemic.
“We need to tighten the borders in order to keep the country open within,” Prime Minister Naftali Bennett said on Sunday.
“Imposing restrictions on the country's borders is not an easy step; however, it is both necessary and temporary,” the premier added.
Israel’s stringent measures follow the World Health Organisation warning that Omicron, first reported by South Africa, was potentially more infectious than other coronavirus variants.
Middle East moves to contain Omicron
The first Omicron case in Israel was detected last week after an infected citizen returned from Malawi.
The Palestinian health ministry on Sunday denied rumours that the variant had also reached the occupied West Bank.
In response to the new variant, Israel has placed 49 African countries and territories on a red list. Residents are allowed to return from those destinations, but they will be transferred briefly to a hotel before being subjected to home quarantine and further testing.
While residents will still be allowed to travel, the Israeli government warned those leaving that “directives may change while they are abroad”.
At Ben Gurion airport, near Tel Aviv, passengers were dismayed by the speed of the changes.
“Now even if you have the booster you have to quarantine, so it just becomes more and more complicated, and cumbersome, and annoying,” said Menashe Assor, 40, an Israeli who lives in New York.
“I think it’s a little ridiculous that it keeps flip-flopping, decisions are made ad hoc and they’re drastic measures that are just made on a whim,” added Mr Assor, who was returning to the US after visiting family in Israel.
Hours ahead of the restrictions coming into force, the airport was busy with mask-wearing passengers. There were few flight disruptions, although cancellations are expected over the next fortnight.
Emirates airline on Sunday announced it was indefinitely postponing the launch of its Dubai to Tel Aviv route, which had been scheduled to start on December 6.
Waiting for security checks at the airport, Amir Arbiv, an Israeli who studies in Italy, was downhearted at the prospect of further border restrictions.
“I’m very sad about the situation and the restrictions, especially the fact that it changed overnight,” said Ms Arbiv, 26, whose parents work in tourism.
“Just now people are coming back to Israel, but again, it’s closing, so it was very short relief,” she added.
As an additional measure, Israel’s security agency has been given the green light to track mobile phones. The Israeli government says the move will help locate people infected with Omicron and “cut the chains of infection”.
Officials have stopped short of imposing other curbs on daily life, with only minor changes to the way large indoor events are handled.
To enter public spaces such as restaurants, residents already have to show a “green pass” proving that they have been vaccinated or recently recovered from a coronavirus infection. They are also required to wear masks indoors, although neither measure is strictly enforced.
About 500 coronavirus cases are registered daily in Israel, health ministry data shows, out of a population of nine million.
The travel restrictions are due to take effect at midnight on Sunday and continue for an initial two weeks.
They coincide with the start of Hanukkah, a Jewish holiday, and come ahead of Christians celebrating Christmas next month.
The restrictions deal a blow to residents of Bethlehem, the focal point of Christmas celebrations as worshippers believe Jesus was born there.
After being devoid of tourists last winter because of the pandemic, tourists had finally started returning to the West Bank city this month.
Under the new regulations, only foreigners who obtain special permission from a government body will be allowed to enter Israel or the Palestinian territories.
Before her flight to Italy, Ms Arbiv described the impact on her parents, who work in a hotel and for a company giving Christian tours, and others in the tourism industry.
“It’s very sad for them as well, to know that their customers cannot come back to Israel even though they booked their tours,” she said.
Infection rates are significantly lower among returning travellers than the general population, according to health ministry data.
On average over the past month, 0.67 per cent of coronavirus tests have been positive in Israel.
This contrasts with 0.13 per cent of travellers from the United States, for example, and 0.14 per cent of people coming from France.
Until now, all arrivals were required to take a PCR test before their journey and on arrival. From Monday, returning residents will have to quarantine for at least three days and have to undergo a third PCR test.