Japan may face a second surge of coronavirus infections, said Kenji Kitahashi, the mayor of the southern port city Kitakyushu.

“We are on the doorstep of a second wave,” he warned, pointing to a string of new infections.

The city, home to about 937,000 residents, had had no new cases for 23 days, said Kitahashi. Then, the virus returned; since last Friday, there have been 14 new cases.

One patient showed no symptoms but tested positive after a precautionary test, according to the mayor.

The city is located in Fukuoka prefecture, where the state of emergency order was lifted on May 14.

The nationwide state of emergency was lifted in some low-risk areas earlier in the month, before being fully lifted everywhere on Monday.