Hundreds of activists have staged an anti-Olympics rally in Tokyo ahead of the opening ceremony.
It comes amid continued consternation in some quarters over the staging of the Games during the coronavirus pandemic.
Just as the Olympics begin, Tokyo has seen a wave of infections. There were 1,359 cases reported on Friday, after 1,979 were reported on Thursday: the highest daily number since January.
Before the opening ceremony, protesters gathered in the capital calling for the Games to be cancelled.
One protester carried a placard calling for the Olympics, which were delayed from last year due to the pandemic, to be “crushed”.
“IOC [the International Olympic Committee] is greed like a devil,” it read. "Olympians are selfish like a child.
“Tokyo Olympics are shame of the world.
“Refuse the Olympic Games!”
Other protesters called for money spent on the Olympics to be used for Japan’s Covid-19 response instead.
One activist was pictured being escorted away by police officers after getting into a row with a supporter of the Games who was in the vicinity of the protest.
The protest later moved to the National Stadium where the opening ceremony was being held. Protesters wearing face masks yelled “stop the Olympics” as they marched, with chanting continuing during the ceremony.
A poll carried out by a Japanese newspaper earlier this week showed more than two-thirds – 68% – of respondents doubted organisers' ability to control the virus.
More than half – 55% – wanted the Games to be scrapped.
Concerns about the Covid situation in Tokyo are so grave that earlier this week, Toshiro Muto, the CEO of the Tokyo Organising Committee, had refused to rule out a last-minute cancellation of the Games.
While the Olympics are still set to continue as planned, there are fears the Games' Covid isolation "bubble" system has already burst after a number of cases emerged among athletes and other people involved.
As of Friday, 106 people linked to the Games had tested positive for the virus. Some 11,000 athletes are set to stay in the Tokyo “village” during the event.
Earlier this month, Japan decided participants would compete in empty venues to minimise the risk of further infections.
Public health experts have warned cases could surge past 2,000 a day in the capital by next month – levels that could drive the city's medical system to breaking point.
The Japanese government, meanwhile, is also under pressure over the slow rollout of the vaccine.
According to Oxford University’s Our World in Data website, 35.3% of the total population had received one dose. This compares to the UK, where almost double – 68.4% – have received a first dose.
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