Japan reported a record 148 daily coronavirus deaths on Friday as the country battles a "fourth wave" of infections that shows no signs of stopping, according to data released by local authorities.

The number of COVID-19 patients with severe symptoms also hit an all-time high, increasing by 33 from the previous day to 1,131, the Health, Labor and Welfare Ministry said.

The nationwide tally of daily cases exceeded 6,000, the highest since mid-January when a second state of emergency was in place.

The Japanese government on Friday decided to extend the current third state of emergency in Tokyo and the greater Osaka area to May 31 and expand it to other areas in an effort to bring down infections and ease the strain on hospitals.

Record daily infections were reported in nine prefectures including Fukuoka and Aichi, both of which will be covered by the state of emergency from Wednesday.

Osaka Prefecture saw 1,005 new infections, while Tokyo reported 907.

Osaka also reported 50 deaths, believed to be the highest daily number ever recorded in a Japanese prefecture since the start of the pandemic.

In the western prefecture, the number of people suffering from severe conditions continues to exceed the number of beds secured for them, forcing some of the cases to be treated in beds initially reserved for those with less severe conditions.

The death toll for neighboring Hyogo Prefecture stood at 39, of whom 25 were residents of a nursing home in Kobe where a cluster was reported.

Japan's previous highest daily death toll was 121 people on Feb. 10.

The state of emergency has been in effect in Tokyo, which is set to host the Summer Olympics in less than three months, as well as Osaka, Kyoto and Hyogo prefectures since April 25.