According to the Iwaki City Fire Department in Fukushima Prefecture, around 6:50 am, there was a report that there was an explosion at the Iwaki Daio Paper factory in Minamidai, Iwaki City.
It is believed that the boiler exploded and the fire was extinguished after about 30 minutes.
One person was taken to the hospital and is conscious and in non-life-threatening condition.
The scene is in a mountainous area about 5 km northwest of Ueda Station on the JR Joban Line in southern Iwaki City, and police and fire departments are investigating the details.