Urban areas such as Tokyo and Osaka are among the nation's 47 prefectures where the rate of hospital beds available for COVID-19 patients stands at less than 20 percent, a Kyodo News survey has shown.

The finding comes amid growing concerns over further strains on Japan's health care system due to the rising number of infections in the capital and elsewhere. All prefectures are now covered by the state of emergency, which was declared by Prime Minister Shinzo Abe on Thursday to curb the spread of the virus heading into the Golden Week holidays through May 6.

The survey, which was based on interviews with local governments on Friday, found that in addition to Tokyo and Osaka, hospital bed vacancy in six other prefectures remains lower than 20 percent. The six are Shiga, Okinawa, Hyogo, Ishikawa, Kagawa and Fukuoka prefectures.