According to the ministry, 16 of the infected are returning passengers from the United States, France, England, the United Arab Emirates and South Africa, while the five others were infected in Israel through close contact with passengers returning from South Africa and the United States.
It added that eight of the 21 infected are unvaccinated, or recovered more than half a year ago.
Another 21 cases of the variant are highly suspected in Israel, but the results of their genomic sequencing tests have yet to be obtained, according to the ministry.
There are also 17 other cases of low suspicion for the variant. Their test results were uncertain and sent for re-testing.