A Nigerian Olympic delegate became the first visitor to the Tokyo Games admitted to hospital with COVID-19, broadcaster TV Asahi said Friday, as Japan battles to stem rising local infections a week before the showpiece event starts.

The individual, a nonathlete in their 60s, tested positive on Thursday evening at the airport with mild symptoms but was hospitalized because of age and pre-existing conditions, the broadcaster said, without giving details.

Organizers have promised that the games, starting on July 23 after being postponed from last year because of the pandemic, will be ¡°safe and secure.¡±