JERUSALEM: Israel on Sunday decided to close its borders to foreign tourists and re-authorise a controversial cellphone tracking programme in a bid to stem the spread of the new Omicron variant of the coronavirus.

"The entry of foreign nationals into Israel is banned except for cases approved by a special committee," Prime Minister Naftali Bennett's office said in a statement, adding that the measure would take effect on Sunday evening.

Israeli citizens will be required to present a negative PCR test and quarantine themselves for three days if they have been vaccinated against the coronavirus and seven days if they have not.

It was only four weeks ago that Israel reopened its borders to foreign tourists after a prolonged closure due to Covid.

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The measure were decided by a cabinet committee tasked with overseeing Israel's Covid response.

Bennett's government has also re-activated a controversial programme initiated under his predecessor Benjamin Netanyahu early in the pandemic that allows the powerful Shin Bet internal security agency to track cellphones as a viral containment measure.

Tracking "will be in order to locate verified (Omicron) cases and thereby cut the chains of infection," Bennett's office said, adding the programme will take effect on Thursday.

The tracking "is restricted only to verified cases of the new strain.

"There will be no widespread and sweeping use for all verified cases as was done in previous waves," it added, stressing the Shin Bet will also not monitor quarantine violations.