Medical experts are urging Japan to test more people for the novel coronavirus and provide more details on infection rates to grasp the scale of COVID-19 cases in the country, after seeing a recent rise in the rate of people testing positive.

Japan has so far conducted polymerase chain reaction tests on more than 130,000 people for the pneumonia-causing virus, a much lower number than many other countries including South Korea, which had conducted more than 520,000 tests by April 14.

While Japan chose to limit the number of tests at the outset of the outbreak to avoid straining its medical system, such an approach has more recently raised fears among experts that the country will not be able to fully trace the spread of the virus and that an explosive spike in infections could go undetected.