The number of coronavirus cases in Japan rose to 20 on Saturday as Prime Minister Shinzo Abe instructed ministers to come up with additional steps to respond to the outbreak.

The health ministry said three more returnees from the virus-hit Chinese city of Wuhan have tested positive, in addition to the 17 cases of infection reported earlier, including some without symptoms. The three were among the Japanese nationals who returned on government-chartered flights last week.

Abe on Saturday stressed the need to make sure people across the country have access to necessary medical examinations and supplies, including masks, as infections have been confirmed in various parts of the country.