Japanese doctors have detected a fast-spreading variant of the new coronavirus first discovered in Britain in three people who had not travelled there, the Health Ministry said on Monday.
The three, aged from their 20s to their 60s and living in Shizuoka prefecture, about 200 km (125 miles) west of Tokyo, first had symptoms in early January, the ministry said.
A health ministry official said that the authorities are looking into how the three became infected but that there was no proof yet that the variant first detected in Britain was spreading in Shizuoka now.
Japan has so far detected 45 cases of new variants of the virus that were first spotted in Britain, South Africa and Brazil, he said.
Japan earlier this month expanded a state of emergency declared in the Tokyo area to seven more prefectures to curb COVID-19 cases.
The country has recorded about 335,000 cases of infection so far, including 4,500 deaths, public broadcaster NHK said.