TOKYO - Japan's top medical adviser blasted International Olympic Committee (IOC) President Thomas Bach on Wednesday for visiting Tokyo again when the country is expanding emergency curbs to contain the COVID-19 pandemic.

Japan will expand states of emergency to eight more prefectures from Friday, taking the total to 21 regions from Hokkaido in the north to the southern island of Okinawa and covering nearly 80% of its population.

In an unusually blunt statement from a Japanese official, Dr Shigeru Omi suggested Bach's decision to fly into Japan again for this week's Paralympics opening ceremony had undermined efforts to persuade people to avoid travel and work from home.

In response, the IOC said Bach's visit had been authorised by the Japanese government and was meant to show support for Paralympic athletes.

"We had said over and over 'What kind of message will the Olympics send to the public'" Omi, the immunologist who chairs the government's coronavirus advisory panel that approved the emergency plan, said in a parliamentary session.

"We're asking people to work from home more. If (IOC) President Bach needs to give a speech (for the Paralympics), why couldn't he do it remotely Why does he have to bother coming all the way here" Omi said, drawing applause from a few lawmakers.

"That kind of plain, common sense should function under these circumstances," he said.

Bach spent over a month in Japan for the Olympic Games, which finished on August 8. The IOC said on Wednesday his latest visit was "part of the support of the IOC to the Paralympic Games and the Paralympic athletes and the strong cooperation between the IOC and the IPC".

Omi's comments underscored the frustration felt by many as the government grapples to bring infections under control. Citizens are growing weary of life under restrictions and companies are ignoring repeated requests to promote work-from-home.

Omi had voiced strong concerns about holding the 2020 Games, while others in the medical community opposed them. He had warned that infections could spread as the public interpreted hosting the Games as a sign that it was safe enough to go about their normal activities.

HOSPITALS NEAR CAPACITY

Nomura Research Institute executive economist Takahide Kiuchi estimated the latest state-of-emergency expansion would lead to an additional economic loss of about 420 billion yen ($3.83 billion), bringing the total fallout from Japan's fourth round of emergency curbs to 3.84 trillion yen.

That dwarfs the 1.68-trillion-yen boost the economy was expected to see from holding the Olympic and Paralympic Games, he estimated.

Months of emergency curbs in the capital, Tokyo, and surrounding areas have failed to reverse a surge in infections and about 90% of the city's critical care beds are occupied.

The state-of-emergency expansion plan will add Hokkaido, Aichi, Hiroshima and five other prefectures starting from Friday through to Sept. 12.

Another four prefectures will be placed under more limited "quasi-emergency" measures, bringing the regions under those curbs to a total of 12 out of Japan's 47 prefectures.

"Maintaining the health system is the top priority to protect the lives of citizens," Prime Minister Yoshihide Suga said.

With hospital beds filled to or nearing capacity, many people have been forced to convalesce at home with some dying before they can get treatment.

Securing oxygen stations and nurses, as well as considering the use of antibody cocktails for outpatients were among the priorities, Economy Minister Yasutoshi Nishimura said earlier.

"The working-age demographic is the driving force (behind the rise in infections)," Nishimura said. "We need to halve the movement of people."

He added that infections transmitted by children as new school terms start were another concern.

The government reported 21,561 new cases and 30 deaths for Tuesday.

($1 = 109.7700 yen)

(Reporting by Chang-Ran Kim and Daniel Leussink; Additional reporting by Sam Nussey; Editing by Jane Wardell, Christian Schmollinger and Andrew Heavens) ((ran.kim@thomsonreuters.com; +81-3-4520-1228))