Three more Japanese athletes and one coach tested positive for COVID-19 at the World Athletics Championships on Monday, the country's athletics federation, the JAAF, said — taking the total number of cases in the delegation up to 15.
The latest group of infections comes after seven members of Japan’s team tested positive on Saturday.
Sprinter Yuki Koike tested positive and missed the men's 200-meter heats on Monday, while Shunsuke Izumiya and Takayuki Kishimoto were scheduled to compete in the men's 400-meter hurdles and 110-meter hurdles.
As a precaution, the remaining members of the Japanese delegation are not sharing common spaces with other delegations, the JAAF said.
Grant Holloway won the 110-meter hurdles title on Sunday. The 400-meter hurdles final takes place on Tuesday.
Organizers have made it mandatory for all workforce, technical and medical officials and media to wear masks in indoor spaces amid "a rise in COVID-19 cases amongst accredited people."
"Athletes and team officials are also required to wear masks in their accommodation and indoor dining and recreation spaces," the statement added.
"It is highly recommended that athletes also wear masks in indoor areas at the competition venue if this does not interfere with their preparation or recovery."