AOMORI (Kyodo) A 13-year-old girl died Sunday and three of her relatives were hospitalized after possibly inhaling toxic volcanic gas in the Hakkoda Mountains near the city of Aomori, police said.

Miki Ito and her 45-year-old mother, Mayumi, were found collapsed on a mountain near the Sukayu hot springs resort, where they had been staying.

Rescuers called to the scene at 6:45 a.m. declared the girl dead. The mother was taken to a nearby hospital with two of her relatives, who felt sick.

The three were not in a life-threatening condition, the rescuers said.

Police said the victims, who had gotten up early to pick edible wild plants, may have inhaled volcanic gas. They were part of a group of nine relatives who arrived at the hot springs resort Saturday evening, the police said. Seven of them went out early Sunday looking for plants.

The police opened a search in the mountains to see if any other people were affected.