The number of new coronavirus cases is on the rise again in Japan. Authorities confirmed more than 500 infections on Wednesday for the first time in two months.

Officials in Tokyo reported 76 new cases, topping 50 for the first time since mid-October. That marked a week-on-week increase for 12 days in a row.

Officials at the US Marine Corps Air Station Iwakuni in Yamaguchi Prefecture, western Japan, say 80 personnel tested positive for the coronavirus. That is the highest number reported on the base in a single day.

At the Marine Corps' Camp Hansen in the southern prefecture of Okinawa, nearly 300 people have been confirmed to be infected so far.

Japan's foreign ministry believes 47 percent of the samples are of the Omicron variant.

Currently only Japanese nationals and returning foreign residents are being allowed into the country. Anyone arriving from countries or territories where Omicron cases have been confirmed must quarantine for three to 10 days in designated facilities.

Health ministry officials confirmed 113 new Omicron cases among those who entered the country between December 17 and 25.