A virus state of emergency in Tokyo and other parts of Japan was extended on Friday, less than three months before the Olympics, with restrictions also imposed in more regions as cases surge.
The emergency measures, less strict than blanket lockdowns in other countries, had been due to end on May 11 but will now continue until the end of the month, Prime Minister Yoshihide Suga said.
"The number of new virus cases is at a high level in major cities, while hospitals continue to be overwhelmed in Osaka and Hyogo prefectures," Suga said.
"Based on this situation, we decided to add Aichi and Fukuoka to the areas under the state of emergency and to extend it until May 31."
Japan's Covid-19 outbreak remains much smaller than in many countries, with just over 10,500 deaths.
But its vaccine rollout is moving slowly and some areas have seen record cases as more infectious variants drive fresh waves of contagion.
Osaka governor Hirofumi Yoshimura has warned the western region's medical system is "reaching breaking point", with reports of Covid-19 patients dying while waiting for an ambulance.
Fukuoka and Aichi were added to the four regions that have been under emergency measures for a fortnight -- Osaka, Hyogo, Kyoto and the capital Tokyo, where the Olympics are due to open on July 23.
The state of emergency restricts commercial activity, with bars and restaurants told to shut or stop serving alcohol, and cinemas and karaoke parlours closed.
But some rules will soon be eased despite the extension, local media reported, such as allowing a limited number of fans back into sports stadiums.
- 'Protect our lives' -
More than 10,000 athletes from 200 countries and regions are due to take part in the pandemic-postponed 2020 Olympics.
Games president Seiko Hashimoto said Friday the organising committee would "welcome" a visit by IOC president Thomas Bach this month, but that it would be "very difficult" to arrange given the prolonged state of emergency.
Japan's government and Games organisers insist the event will go ahead safely -- although polls show most Japanese people support cancellation or another delay.
More than 210,000 people have signed an online petition titled "Cancel the Tokyo Olympics to protect our lives", launched Wednesday by a lawyer and former Tokyo gubernatorial candidate.
And a hospital in western Tokyo put up signs in its windows saying "Olympics impossible!", with the facility's chief telling the Asahi Shimbun daily its nurses were already overburdened.
Pfizer and its German partner BioNTech on Thursday announced a deal with the International Olympic Committee to provide vaccines to competitors and staff at the Tokyo Games.
But Japan's own vaccine programme is progressing cautiously, with under one percent of the population having received two shots of the Pfizer vaccine, the only jab authorised so far.
World Athletics boss Sebastian Coe, who attended a scaled-back rehearsal for the Olympic marathon in the northern city of Sapporo on Wednesday, said Friday he recognised the "challenging times" faced by Japan.
"The safety of our athletes is important to us, but also the safety of the local community," he told reporters in Tokyo, noting that athletes at the marathon test had found the virus countermeasures "comforting".
The pandemic has disrupted Olympic test events, with several postponed, cancelled or moved abroad.
But the Diving World Cup and a rowing qualifier went ahead this week in Tokyo with athletes from overseas, with Tokyo 2020 organisers calling the diving event "very successful".
"All participants fully complied with the measures in place," Tokyo 2020 said in a statement after the six-day event, at which 224 athletes took part.
Several sections of the torch relay have also been moved off-road to prevent people gathering to watch.
Fukuoka's governor said he wants it to be pulled from public roads when it passes through the region next week.
Olympics organisers are yet to decide how many fans -- if any -- will be allowed at the Games, with overseas spectators already barred from attending.