Olympic fans in Japan reacted with weary resignation to a ban on Tokyo Games spectators on Friday, as newspaper editorials warned it may not be enough to stop the virus.

Kyoko Ishikawa, who has attended every Summer Games over the past 30 years, told AFP she "already expected" the decision to ban fans from most Olympic events, which was announced late Thursday.

But she said she still hopes to have "an opportunity to connect people" through online events.

"We already expected it, so it's not really surprising and it's not getting me down," said Ishikawa, who has become a familiar face at Olympic venues over the years in her traditional Japanese outfit and 'hachimaki' headband.

Tokyo Olympic organisers have banned spectators from attending most events.
Tokyo Olympic organisers have banned spectators from attending most events. AFP / Philip FONG

"Now, what I have to do is ask how I can still create an opportunity to connect people around the world through the Olympic Games."

Ishikawa said she still hopes to attend the Paralympics -- set to begin on August 24. Organisers will decide attendance limits for that after the Olympics ends.

"You can't change the situation. What you can do is just leverage what you have to be the best, to maximise the things that you can do," she said.

With infections rising in the capital, Prime Minister Yoshihide Suga announced Thursday that Tokyo would be under a virus state of emergency from July 12 until August 22.

The measure is significantly looser than lockdowns seen elsewhere, largely limiting alcohol sales, shortening opening hours for restaurants and capping event attendance at 5,000 people.

Kyoko Ishikawa has been to every Summer Olympics for the past 30 years
Kyoko Ishikawa has been to every Summer Olympics for the past 30 years AFP / Philip FONG

But it signals a growing concern about the current rate of infections and appears to have piled pressure on Olympic organisers, who had previously hoped to have up to 10,000 local fans in venues after barring overseas spectators.

The Nikkei Shimbun newspaper said in an editorial Friday that banning fans from the Games alone would not stop the spread of the virus.

"Even with no spectators, there are concerns that infections could spread, with tens of thousands of Olympic-related visitors -- not including athletes -- coming to Japan," the paper said.

"It is necessary to test thoroughly and control their activities."

The Asahi Shimbun newspaper, an official Games sponsor that ran an editorial called for it to be cancelled in May, accused the government of trying to "ram through" the event.

"School sports days and local festivals have been cancelled or postponed, and doubts and frustrations over the special treatment of the Olympics could affect efforts to prevent infections," it said.

There was also anger from some Japanese social media users, with the phrase "no-spectator Olympics" trending on Twitter.

"There was no need to rebuild the National Stadium," wrote one user, referring to the Kengo Kuma-designed main Olympic venue, which was built to the tune of an estimated $1.4 billion.

"An Olympics with no spectators means it has become an Olympics for aristocrats, as only Olympic aristocrats will get to watch the Games," wrote another.