A freezing Hokkaido city that has become a red flag for Japan's winter vulnerability to the coronavirus pandemic is weathering the worst of its COVID-19 crisis, local medical officials say, as military nurses take the strain from drained hospital staff.

The city of Asahikawa was hit by outbreaks at two major hospitals, exacerbated by subzero temperatures and restricted ventilation that can promote the virus's spread. But a voluntary lockdown, combined with medical reinforcements sent by central government last week, have helped the city stabilize — for now.

There are now signs the cluster crisis is "peaking out," said Yasutaka Kakinoki, a hematologist at Asahikawa City Hospital. That's a relief, he said by phone, as staff have been pushed to the brink fighting the steady rise in COVID-19 cases over the last two months.