On Monday, Japan took some of the strictest steps globally by closing its borders to non-Japanese for about a month in light of the emergence of Omicron. A day later, Japan's first Omicron case - in a Namibian diplomat - was discovered.
The border closing affecting residents will be in effect from midnight on Wednesday for at least a month and will apply to foreign residents from South Africa, Eswatini, Namibia, Zambia, Malawi, Mozambique, Lesotho, Angola, Botswana and Zimbabwe, Reuters reported.
"From the view of prevention, we won't just restrict new entry by foreigners but also returning foreigners with resident status, unless there are special extenuating circumstances," chief cabinet secretary Hirokazu Matsuno told a news conference on Wednesday.
"We will maintain a sense of urgency and keep track of the situation in various countries to be able to respond quickly and flexibly."
Of other passengers on the plane with the Namibian diplomat, he said none of the 70 people designated as close contacts have shown signs of falling ill. Health Minister Shigeyuki Goto later said his ministry was in contact with local governments in keeping an eye on these people.
On Wednesday, media reported that another case had been confirmed in Japan, with NHK public television saying it was a foreign man and FNN television saying it was a traveler from Peru.
Japanese border measures were loosened slightly a few weeks ago, but all of those changes have been rolled back in a move generally applauded by the public and accepted by business leaders, although some sectors of the economy dependent on foreign trainees could be hit if the closing is extended.