Japan’s lax enforcement of rules stopping travelers using public transportation from airports is turning into a vulnerability in its efforts to curb the spread of COVID-19 — a problem that could intensify as the nation expects a surge in new arrivals from abroad toward the end of the year.

Under the current border control policy, all travelers from abroad, Japanese or foreign, are asked not to use public transportation for the entirety of their two-week quarantine period, including immediately after arrival, due to the risk of spreading the virus.

But reports have emerged in recent weeks and days that some of them have been spotted ignoring this request when leaving airports, relying on trains and buses instead to get back home or visit nearby hotels for the two-week quarantine.