Rescue workers found 13 bodies, most of them buried by mudslides, on Izu Oshima island about 120 kilometres south of Tokyo, police and town officials said. Dozens of homes were destroyed, and more than 50 people are missing.
"We have no idea how bad the extent of damage could be," town official Hinani Uematsu said.
NHK public television showed rescue workers struggling to dig a woman out of a heap of debris as she shrieked in pain. A rescuer told NHK that he almost walked by the spot without seeing the woman in the debris until she cried out, "Help!"