People wearing face masks walk in Tokyo's Shinjuku area on Nov. 12, 2020, amid a surge in coronavirus cases across Japan. (Kyodo) ==Kyodo

Japan on Thursday confirmed 1,660 new cases of coronavirus, a record daily high since the outbreak of the virus earlier this year, amid signs of what some health experts refer to as a possible "third wave" of infections as the winter season approaches.

The nationwide tally, compiled by Kyodo News from official information, comes as urban areas such as Tokyo and Osaka, and the country's northernmost main island of Hokkaido, a popular tourist destination, are seeing a spike in the number of new cases.

After a meeting of a government subcommittee on virus countermeasures, Yasutoshi Nishimura, the minister in charge of the Japanese government's coronavirus response, warned that "a surge (in infections) on par with the one in summer is on its way."

The previous single-day record of 1,597 new cases nationwide was logged on Aug. 7.

The experts have attributed the resurgence in infections to cold weather as people spend more time indoors. Toshio Nakagawa, head of the Japan Medical Association, has described the latest situation as "a third wave" of the coronavirus.

Since September, single-day coronavirus cases across the country had hovered between 300 and 600 before they started increasing in October. To date, more than 114,000 confirmed cases have been reported across Japan, including about 700 from a cruise ship that was quarantined in Yokohama in February. Over 1,800 deaths have been attributed to the coronavirus.

Shigeru Omi, head of the subcommittee made up of health experts, warned at a press conference after Thursday's meeting that if "sufficient measures are not taken, there will be no other way but to implement restrictions on social and economic activities."

After the central government declared a state of emergency in April amid rising infections, the number of COVID-19 cases surged again in summer.

In Tokyo alone, 393 new cases of coronavirus infections were confirmed Thursday by the metropolitan government, bringing its cumulative total to 33,770, the highest by far among the country's 47 prefectures.

The capital's single-day infection figure topped 300 for the second consecutive day. The highest daily infection figure in Tokyo of 472 was recorded on Aug. 1.

Hokkaido, which has recently seen a surge of coronavirus infections, confirmed on Thursday a record 236 cases, topping 100 for the eighth straight day. The cumulative tally of cases stood at 4,797 in Hokkaido, known for its cold temperatures, with 122 deaths.

On the same day, Nishimura was instructed by Prime Minister Yoshihide Suga to continue working with prefectural governors to prevent an "explosive spread" of COVID-19.

Nishimura said while the situation does not warrant a state of emergency declaration, should infections worsen, economic activities such as operations of eateries and other businesses could be restricted.

Japan also currently limits large crowds to 50 percent of a venue's capacity, and a plan to extend the cap until the end of February beyond its Nov. 30 deadline was approved at the pandemic response meeting on Thursday.

"We may review the policy (to restrict the number of participants at events)" if the virus spreads further, Nishimura said at a press conference following the meeting.

Japan had raised the limit on attendance at large events from 5,000 to 10,000 in September while keeping the 50 percent cap.

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