Photo/Illutration An electron microscope image of the novel coronavirus (Provided by the U.S. National Institute of Allergy and Infectious Diseases)

Japan reported a single-day high of 53 deaths from COVID-19 on Dec. 15 after the number of infected patients in serious condition set a record for the fourth straight day.

The daily death toll as of 8:30 p.m. exceeded the previous high of 47 confirmed on both Dec. 8 and Dec. 14. So far, 2,702 people have died of the disease in Japan.

Of the 53 fatalities, 11 were reported in Hokkaido, 10 were in Osaka Prefecture, nine were in Tokyo and five were in Hyogo Prefecture.

Overall, 2,433 novel coronavirus infections were confirmed on Dec. 15, breaking the previous Tuesday record of 2,173 reported on Dec. 8.

Fewer new infections are usually reported on Mondays and Tuesdays because the numbers reflect cases from about three days earlier, close to the weekend, when fewer people tend to be tested for the virus.

The number of serious cases nationwide rose by four from the day before to 592 as of midnight on Dec. 14, the fourth straight daily record, according to the health ministry.

Tokyo confirmed 460 new COVID-19 cases on Dec. 15. It also said the number of patients in serious condition increased by five to 78, the highest since a state of emergency was lifted for Tokyo in late May.

The capital defines serious cases as those requiring ventilators or extracorporeal membrane oxygenation (ECMO) devices.

The Kanagawa and Saitama prefectural governments separately asked some municipalities that have entertainment districts in their jurisdictions to ask alcohol-serving restaurants and karaoke parlors to extend the period of closing by 10 p.m.