TOKYO - Japan has confirmed its first case of infection by the new Omicron variant of the coronavirus, a government source said Tuesday, less than a week after it was first discovered in South Africa.

A man in his 30s was found to be infected with the heavily mutated strain after arriving from Namibia at Narita airport near Tokyo on Sunday, according to the source.

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The World Health Organization has warned the Omicron variant, which has already been confirmed in Europe, Canada, Israel and Hong Kong, may be more transmissible or evade immunity from previous infections and vaccines.

Concerns over the variant have prompted a number of countries to tighten travel restrictions, with Japan closing its borders to new arrivals of foreigners from Tuesday and requiring citizens and foreigners with resident status returning from high-risk areas to quarantine up to 10 days in a government-designated facility.

Prime Minister Fumio Kishida vowed to take every precaution to "avoid the worst-case scenario" in announcing the measures, which come just three weeks after Japan eased entry rules for businesspeople, international students and participants in its technical internship program.

The man who arrived from Namibia tested positive for the coronavirus upon his arrival and samples were being tested at the National Institute of Infectious Diseases to confirm whether it was the Omicron variant.

==Kyodo

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