People walk on a street in Tokyo, Japan on Monday. Japan has entered the "fifth wave" of its COVID-19 outbreak. More than 10,000 people were newly diagnosed on Sunday, the fourth consecutive day the figure has been above 10,000. Prefectures including Saitama, Chiba and Kanagawa declared a state of emergency on Monday. Photo: IC

Japan said on Thursday it will extend emergency COVID-19 restrictions in Tokyo and other regions until the end of September to curb infections and prevent hospitals from being overwhelmed, saying it was too early to let down its guard.

Japan has been struggling with a fifth wave of the virus and August extended its long-running curbs until Sunday to cover about 80 percent of its population. However, the number of severe cases and the strain on the medical system have not eased sufficiently in Tokyo and surrounding areas to allow restrictions to be lifted. The government will extend the measures until September 30, including for Osaka, Economy Minister Yasutoshi Nishimura said after meeting with an advisory panel, which ratified the plan.

Japan's emergency curbs have centered on asking restaurants to close early and refrain from serving alcohol.

Some signs of improvement around the nation mean that two prefectures out of 21 will move from the state of emergency measures to more targeted restrictions, while a number of other prefectures will remove all curbs.

"I believe we're starting to see results, but it's still too early to lower our guard," Health Minister Norihisa Tamura said at the meeting. The plan will be formalized at a government task force meeting later on Thursday and announced by Prime Minister Yoshihide Suga at a news conference. The Nikkei daily, meanwhile, reported that the government is moving toward easing international entry restrictions by reducing the quarantine time for people returning from overseas to 10 days from the current 14 if they have had vaccines approved by the Japanese government.

Local media said other measures, such as allowing restaurants to extend their opening hours, could be introduced as the number of vaccinations in the nation rises.