Shunji Sekine, 71, opened a temporary clinic in early May in Namie, Fukushima Prefecture, to examine residents who began visiting their homes after evacuating the coastal town during the 2011 nuclear disaster.

"It would be a problem if they got injured during their temporary visits," said Sekine, who has been practicing medicine in the town since 1997. "I want to be here for patients who need me."

The district where the town's office building was situated was part of the exclusion zone set up to protect residents from radiation exposure from the Fukushima No. 1 power plant, some 10 km south.