TEL AVIV — Israel will forbid the entry of noncitizens for two weeks, starting at midnight Sunday night, in an attempt to stem the spread of the omicron coronavirus variant in Israel and to allow experts time to assess its level of transmissibility and resistance to existing vaccines.

The newest variant, which was first detected in South Africa and which experts say may spread two to six times as quickly as the delta variant, is confirmed in one person and suspected in seven others in Israel. Only three of the suspected cases had recently returned from abroad, raising concern that the variant’s transmission has already begun within Israel.

The United States, the European Union and Britain have begun implementing travel bans and restrictions for people coming from South Africa and neighboring countries. Israel is the first country to completely shut its borders because of the omicron variant.

At a three-hour cabinet meeting on Saturday night, the government decided to tighten quarantine rules, reinstate the role of the Israeli internal security service, Shin Bet, in surveilling the cellphones of people confirmed to be carrying the variant, and require events of more than 50 participants to apply a Green Pass system, by which participants must show proof of vaccination or recovery. There are no directives to cancel events for the Jewish holiday of Hanukkah, which starts Sunday night.

The United States and several other countries imposed travel restrictions on South Africa and other African countries after the omicron variant was discovered. (Amber Ferguson/The Washington Post)

“The key here is caution and minimal risk,” Prime Minister Naftali Bennett said Saturday night. He said that the government is looking to keep the economy and schools open, as it had done thanks in part to the rollout of the booster shot program during the delta wave.

In an interview with 103FM radio on Sunday, Health Ministry Director General Nachman Ash said that Israel’s response “isn’t hysteria, but concern. . . . We want to at least be able to delay the variant’s entry into Israel.”

Israel has defined all countries in Africa, except Morocco and Egypt — with which Israel has diplomatic ties — as “red.” Israelis landing from “red” countries must take a PCR test upon landing, enter quarantine at a coronavirus hotel, and then, pending negative results, complete a seven-day home quarantine that can be ended with a negative PCR test on Day 7.

Israelis returning from any non-red country, including the fully vaccinated, will also be required, in addition to taking a PCR test on landing as has already been the protocol, to enter a three-day home quarantine, after which they must receive a negative PCR test.

The government announced plans to obtain 10 million PCR test kits modified to detect the new variant, launch a pilot program to install air filters in classrooms and day-care facilities, and expand sewage testing across the country to detect new cases.

Israel’s sole confirmed omicron case is a 34-year-old foreign worker from Malawi who came to Israel last week via South Africa and Dubai. After receiving a text message that she was required to quarantine, she slept one night at a coronavirus hotel in Tel Aviv, then took a four-hour public bus ride to the southern city of Eilat, where she stayed with a friend. Since Friday, the health-care system and law enforcement agencies have tracked her down, along with dozens of passengers who were on her Eilat-bound bus.

Following the first coronavirus outbreaks in March 2020, Israel issued an emergency order for Shin Bet to access civilian cellphone data to conduct contact tracing for confirmed cases. The measure was halted a year later, following multiple requests from civil rights organizations arguing that it violated privacy and freedom laws.

With its digitized, universal health-care system, Israel was among the first countries in the world to successfully roll out vaccination, and later booster shots, on a wide scale. Nearly half of the population has received a booster shoot. Last week, Israel opened up vaccinations to children as young as 5 in an effort to fight an uptick in infection rates among children.

Ash, the Health Ministry director general, said the omicron variant, with its unprecedented constellation of mutations, was the “most concerning that there has been so far,” but added that experts still believe the existing vaccines will prevent the most serious infections.

Read more: