Defense Minister Taro Kono on Tuesday drew attention to “several problems” with the U.S. military’s prevention measures after coronavirus infections at five of its bases in Okinawa Prefecture surged to a total of 100 cases.

“Several problems with the U.S. military's preventive measures have been discovered,” Kono told a news conference, adding that the American side had vowed to tackle the issues thoroughly.

Pressed for specifics on the “problems,” Kono did not reveal details. However, reports of U.S. personnel leaving base for beach parties and visits to nightlife districts around Independence Day on July 4 have stoked concern among residents, with even Okinawa Gov. Denny Tamaki alluding to this as having played a possible role in the outbreak.