Tokyo health officials appealed on Tuesday for more than 800 theatregoers to get tested for the novel coronavirus after a production starring Japanese boy-band members was found to be the source of at least 37 cases.

As the number of virus infections continues to rise in Japan's capital city, the Tokyo government said it was focusing on a 190-seat theater in the Shinjuku entertainment district, where infections have also been traced to cabaret clubs.

Japan is pushing ahead with opening up parts of the country, with plans to reopen a runway at one of the country's biggest airports, even as infections persist in major cities, rural areas and U.S. military bases.