Authorities in Ishikawa Prefecture's Wajima City suspect a woman in her 70s may have died alone in a temporary house built for evacuees from areas hit by the massive New Year's Day earthquake.

City and prefectural authorities say this could be the first solitary death in temporary housing in Ishikawa. More than 4,000 units were built there after the quake.

The city authorities say the woman's son asked police last week to join him in visiting her, as she had not answered his calls, and found her dead. The cause of her death is not known.

The woman had initially taken shelter outside the city, but later moved to the temporary house.

Four days before she was found dead, a neighbor saw her taking out trash. That was her last known appearance.

The city sends public health nurses to visit temporary houses, but officials say they do not know when the last visit to her home was made and other details.

Wajima city official Yamamoto Toshiharu said at a regular news conference that it was regrettable that the death happened at a time when the city is boosting efforts to prevent people from dying alone or from disaster-related causes.

He also said the city will keep a closer eye on all evacuees living alone and enhance community functions to prevent a recurrence.

Wajima city plans to entrust private groups with visiting temporary houses more frequently from June.