Tokyo organizers plan to prepare 300 hotel rooms for athletes who test positive for the coronavirus but show no or minor COVID-19 symptoms, at this summer's Olympic Games, Kyodo news agency said on Sunday.

Japan's government is placing Tokyo under a month-long state of "quasi-emergency" from Monday to combat surging infections, less than a month after a broader state of emergency was lifted for the capital and Olympic host city.

The Tokyo organizing committee plans to reserve an entire hotel located a few kilometers away from the athletes' village in the Harumi waterfront district, which will likely cost several million dollars, Kyodo said, citing several unnamed sources.

Coronavirus-positive athletes and other Games participants who do not require hospitalization will be quarantined in the rooms for 10 days in principle, and medical staff will treat them around the clock, it said.

The committee will also prepare about 30 special vehicles to transport the patients to the hotel, according to Kyodo.

Athletes will receive COVID-19 tests at least every four days under rules unveiled in February for the Tokyo Games, scheduled to begin in late July after a one-year delay due to the pandemic. More guidance on isolation and testing is to come in April.

Japan has recorded more than 500,000 infections and nearly 9,400 deaths, public broadcaster NHK said on Saturday, low compared to most other major economies. But concerns about the new wave of infections are rising ahead of the Games.