Russia's military has conducted surface-to-air missile drills on at least one of four islands claimed by Japan.
Russia's Eastern Military District says the S-300 air defense system was moved from a location in the country's Far East.
A hospital in the western Japanese city of Kobe has found that about 3 percent of its outpatients carry coronavirus antibodies, indicating they were infected at one point.
A group of doctors, mainly from Kobe City Medical Center General Hospital, collected 1,000 blood samples from patients who visited the hospital for reasons other than coronavirus symptoms between late March and early April.