Japan's health ministry says the number of coronavirus cases across the country has risen for the third straight week.

The ministry says about 5,000 medical institutions nationwide reported 17,379 cases in the seven-day period through Sunday. That was up 3,796 from the previous week.

The ministry also says the average number of patients per institution stood at 3.52 nationwide for the week. That represents a week-on-week rise of 28 percent.

The average climbed in all 47 of the country's prefectures. Hokkaido had the highest number at 7.82, followed by Yamanashi with 7.76, Nagano with 6.64, Gifu with 5 and Aichi with 4.8.

The ministry says about 500 institutions reported that 1,468 people were hospitalized with COVID-19 during the week, up 445 from a week earlier.

Officials are calling on people to continue anti-infection measures, saying infections tend to surge in winter.