Olympic organisers are "extremely worried" about the impact the spread of the coronavirus could have on the Tokyo Games.

In excess of 24,300 cases of the virus have been recorded in China, with 490 people confirmed dead.

A cruise ship in the Japanese port of Yokohama has been quarantined after 10 people on board tested positive.

Tokyo Organising Committee chief executive Toshiro Muto has expressed his concern over the epidemic five months before the Olympics get under way.

"We are extremely worried in the sense that the spread of the infectious virus could pour cold water on momentum for the Games," Muto said.

"I hope that it can be eradicated as quickly as possible. We plan to cooperate with the IOC (International Olympic Committee), the IPC (International Paralympic Committee), the government and the city of Tokyo to tackle the disease."

Saburo Kawabuchi, head of the athletes' village, said: "I hope from my heart that we can overcome this (virus) and have a smooth Olympics.

"We will do everything we can to protect the athletes to allow them to produce their best performances."

The IOC last week refuted reports that the Games could be cancelled.

An IOC statement said: "Countermeasures against infectious diseases constitute an important part of Tokyo 2020's plans to host a safe and secure Games.

"Tokyo 2020 will continue to collaborate with all relevant organisations which carefully monitor any incidence of infectious diseases and will review any countermeasures."