Factbox: Coronavirus cases at the Tokyo Olympics

The Tokyo 2020 Olympics, postponed for a year due to the coronavirus pandemic, is being held under unprecedented conditions including tight quarantine rules to prevent the spread of COVID-19.

However, a number of cases have emerged among athletes and other people involved with the Games. Following are the cases, with the latest listed first:

AUG 4: Twenty nine people, including four athletes, tested positive for COVID-19, bringing the total Games-linked number since July 1 to 322, Tokyo 2020 organisers said.

AUG 3: Greece have withdrawn from artistic swimming competitions after four of their athletes tested positive for COVID-19, the Greek Olympic Committee said.

Eighteen people, including one volunteer worker and a member of the media, tested positive for the coronavirus, Tokyo organisers said.

AUG 2: Seventeen people tested positive for the virus, the organisers said.

AUG 1: Eighteen people, including one athlete staying at the Olympic village, tested positive for the coronavirus, bringing the total Games-linked number since July 1 to 259, Tokyo organisers said.

Tokyo 2020 CEO Toshiro Muto said that, with more than 30,000 tests conducted every day, organisers had managed to locate positive cases, isolate them swiftly and take appropriate measures to prevent the spread of infection.

JULY 31: Trinidad & Tobago long jumper Andwuelle Wright and 400 metres hurdler Sparkle Ann McKnight have been withdrawn from the Games after they tested positive for COVID-19, the country's Olympic committee said.

Fourteen contractors and seven members of the Games personnel tested positive for the coronavirus, Tokyo organisers said.

JULY 30: Twenty-seven people including three athletes and four volunteer workers tested positive for the virus.

JULY 29: Pole vaulters Sam Kendricks of the United States and Argentina's German Chiaraviglio have been ruled out of the Olympics after testing positive for COVID-19.

Twenty four people tested positive for the virus, Tokyo organisers said. They also said two Olympic-related people from overseas with COVID-19 had been hospitalised but neither case was serious.

JULY 28: Sixteen people, including two members of the media, tested positive for the virus, Tokyo organisers said.

JULY 27: One athlete and five other Games-related people tested positive for the coronavirus, the organisers said.

JULY 26: The Dutch men's tennis doubles team withdrew from the Tokyo Games after one of the pair, Jean-Julien Rojer, tested positive for COVID-19, the International Tennis Federation said.

Fifteen people including three athletes tested positive, Tokyo organisers said.

JULY 25: Dutch rowing coach Josy Verdonkschot tested positive for coronavirus and went into a 10-day quarantine, the Netherlands Olympic Committee said.

Ten people, including two athletes and one member of the media, also tested positive for coronavirus, the organisers said.

JULY 24: One athlete, two members of Games staff and 14 contractors tested positive for the coronavirus, Tokyo organisers said.

Japan's Miki Ishii and Megumi Murakami won the first women's match of the beach volleyball tournament by default after their Czech opponents withdrew due to COVID-19. Marketa Nausch-Slukova tested positive this week, forcing her and partner Barbora Hermannova to pull out. Six members of the Czech Olympic team have tested positive.

JULY 23: Belgium's Jelle Geens will miss the Olympics men's individual triathlon on Monday after testing COVID-19 positive but is still hoping to travel to Tokyo for the mixed relay on July 31, the Belgian National Olympic Committee said.

German cyclist Simon Geschke tested positive and had pulled out of Saturday's road race, his team said.

Dutch rower Finn Florijn tested positive at the Tokyo Olympics and will no longer participate in competition, the Royal Dutch Rowing Federation said.

Nineteen people including three athletes and three members of the media tested positive for COVID-19, organisers said.

JULY 22: Nausch-Slukova becomes the third athlete in the Czech delegation to be found to have contracted the virus, her Olympic committee said. Pavel Sirucek and Ondrej Perusic of the men's table tennis and beach volleyball teams respectively have also tested positive.

Twelve people, including two athletes staying at the Olympic village, tested positive, Tokyo organisers said. The rest were six contractors and four members of the Games personnel.

JULY 21: Dutch skateboarder Candy Jacobs said she tested positive for COVID-19 and was heartbroken that she could not participate in the Games.

A Chilean female taekwondo player plans to withdraw from the Games after testing positive for the coronavirus, public broadcaster NHK reported.

The organisers said eight people, including an athlete who is not a resident of Japan and six contractors, tested positive. The name, nationality and other details of the athlete were not disclosed.

JULY 20: Nine people, including one athlete staying at the Olympic village, tested positive for the novel coronavirus, the organisers said. The other eight were a volunteer worker, a member of the Games personnel and six contractors.

JULY 19: Three people -- one member of the Games personnel, one member of the media and one contractor -- tested positive, organisers said. Twenty-one people in the South African soccer delegation have been categorised as close contacts, following positive test results for two of their soccer players. The number of close contacts was later revised down to 18.

Those identified as close contacts can still take part in competition if they return a negative test result within six hours of the start of their event.

An alternate on the U.S. women's gymnastics team tests positive and another alternate is a close contact, USA Gymnastics say. They remain at the team's training camp east of Tokyo.

JULY 18: Ten people, including two South African male soccer players staying at the athletes' village, tested positive, organisers said. This is the first time athletes have been found positive within the village. The others are an athlete serving a 14-day quarantine, one member of the media, one contractor and five Games personnel.

JULY 17: Fifteen people test positive, the organisers say, including the first case at the athletes' village -- a visitor from abroad involved in organising the Games. The rest are two members of the media, seven contractors and five members of Games staff.

JULY 16: A member of the Nigerian Olympics delegation tested positive at Narita airport, media reported. The person, in their 60s, has only light symptoms but was admitted to hospital because of their age and pre-existing conditions, TV Asahi says, adding it was the first COVID-19 hospitalisation of an Olympics-related visitor.

An Olympic-related non-resident serving a 14-day quarantine tests positive for the virus, the organisers say, without giving further details. Three Tokyo 2020 contractors, all of whom are residents of Japan, also tested positive, organisers say.

JULY 15: Eight athletes from the Kenya women's rugby team are classified as close contacts after a positive coronavirus case is found on their flight to Tokyo, says an official in Kurume city, where they were set to hold a training camp.

An Olympic athlete under a 14-day quarantine period tests positive for the virus before moving to the Olympic Village, the organising committee reports, without giving details. It says one member of the Games personnel and four Tokyo 2020 contractors also tested positive.

JULY 14: A masseur for the Russian women's rugby sevens team tests positive, forcing the team into isolation for two days, the RIA news agency reports. Officials in Munakata, southwestern Japan, confirm one staff member was hospitalised and say none of the team members could be considered a close contact.

The refugee Olympic team delays its arrival in Japan after a team official tests positive in Doha.

Seven staff at a hotel in Hamamatsu, central Japan, where dozens of Brazilian athletes are staying, test positive, a city official says.

Twenty-one members of the South African rugby team are in isolation after they are believed to have been in close contact with a case on their flight.

JULY 9: An Israeli athlete test positive, according to reports.

JULY 4: A member of Serbia's rowing team tests positive on arrival. The other four team members are isolated as close contacts.

JUNE 23: A Ugandan athlete tests positive, according to Izumisano officials.

JUNE 20: A coach with Uganda's squad tests positive on arrival at Narita airport and is quarantined at a government-designated facility. The rest of the team head by bus for their host city, Izumisano.