Taiwan authorities say they have put more than 100 people under quarantine while they investigate the first possible local case of coronavirus infection in more than two months - a Japanese woman who tested positive last week.
Taiwan's early and effective response has kept the pandemic at bay, with just 446 infections and seven deaths, the majority of cases being imported and having already recovered.
Taiwan's Central Epidemic Command Centre said Japan had notified them on Tuesday that the woman, who arrived on the island as a student in late February, tested positive after returning to Japan on June 20 though she was asymptomatic.
More than 100 people who had contact with her in Taiwan have been placed under quarantine, it added.
Health Minister Chen Shih-chung told reporters in Taipei authorities were awaiting further details before formally classifying the case but that it could have been acquired while she was in Taiwan and he could not rule out local transmission.
"Taiwan has already seen 73 days with no local cases but we must still raise our vigilance," he added.
Taiwan effectively closed its borders to most foreigners in mid-March, and has been extremely cautious about re-opening them in case of a second wave of infections.
Life in Taiwan has generally carried on as normal with none of the lockdowns seen in other parts of the world, though the government has encouraged social distancing and face masks are widely worn in public.