An Olympic rings monument in Tokyo's Odaiba waterfront area on Wednesday. Around 10,000 of the 80,000 volunteers who signed up at the Tokyo Olympic and Paralympic Games have quit, NHK reported Wednesday, citing organizers. Photo: VCG

A member of the Uganda Olympic team has tested positive for coronavirus on arrival in Japan, just over a month before the pandemic-postponed Games, officials said.

The first group to arrive from Uganda - a nine-strong party, including boxers, coaches and officials - landed at Tokyo's Narita airport on Saturday. They are the second team to arrive after Australia women's softball squad on June 1.

But one of the African nation's delegation tested positive during screening at the airport, a government official told reporters. The person tested twice but their condition remained unknown, reported local media.

"I heard the person has been isolated based on regulations," Hidemasa Nakamura, the Tokyo 2020 Games delivery officer, told reporters, renewing a pledge to take strict measures against infections.

Public broadcaster NHK said the group had all been vaccinated and tested negative in Uganda before they came to Japan.

The team was originally due to have arrived in Japan on Wednesday, but their flight was canceled following a surge in COVID-19 cases in Uganda, local media said.

The other members of the Ugandan party have already left the airport for Osaka, western Japan, where they will train ahead of the Games.

This was the first case showing positive COVID-19 test results among Olympic arrivals from overseas, local media said.

Last week organizers released virus guidelines for athletes as part of their effort to hold the Games safely even though the pandemic has not yet been brought under control.

Organizers said they would meet on Monday to discuss how many domestic spectators to allow, if any, with reports suggesting they would opt for a cap of 10,000 people.

Nippon Television said organizers were considering setting the upper limit of spectators, including guests and officials, at 20,000 for the July 23 opening ceremony.

Olympic fans from abroad are already banned from attending the postponed event.