Japan rules out changes to COVID-19 curbs

And on Thursday, the governor of neighboring Kyoto prefecture said that a community infection was confirmed in a woman in her 20s, with authorities investigating seven of her close contacts.

The government has started preparations to expand free testing to people who don't have COVID-19 symptoms in an attempt to prevent the spread of the Omicron variant, news agency Jiji reported on Thursday citing unnamed government sources.

Shigeru Omi, the nation's top health advisor, urged caution before people travel or gather with family and friends during the holiday season.

"Now that the Omicron strain has been confirmed as a community-acquired infection, there are concerns that it may spread further, so please be cautious when holding year-end or New Year's parties," he told reporters.