The Tokyo High Court on Monday rejected a claim that deaths and injuries from the 2014 eruption of Mount Ontake were due to the Meteorological Agency's failure to raise the volcanic alert level for the mountain.

Presiding Judge Takeo Tsutsui upheld a lower court ruling dismissing a damages claim by victims' families and overturned the lower court's finding that Meteorological Agency officials violated their duty of care.

The 32 plaintiffs had demanded a total of ¥376 million ($2.5 million) from the central and Nagano governments over the volcanic disaster, which left 58 people dead and five others missing.

In July 2022, the Matsumoto branch of the Nagano District Court determined that agency officials had neglected their duty of care by maintaining the alert level for the volcano, which straddles Nagano and Gifu prefectures, at Level 1 without sufficiently considering data that may have hinted at future eruptions.

Still, the branch did not recognize a causal relationship between the officials' actions and the deaths and injuries of hikers, saying that entry restrictions would not have been introduced in time even if the alert level had been raised.

"Mount Ontake is not a volcano that frequently erupts, and the understanding of volcanology was not sufficiently advanced at the time," Tsutsui said in Monday's ruling, finding that it would have been difficult to decide to raise the alert level based on theoretically sound evidence.

Regarding data on the movement of the earth's crust, which the lower court focused on as a precursor event to the eruption, Tsutsui ruled that the Meteorological Agency was unable to identify the event as crustal movement, as it was too subtle to differentiate from noise.

The officials' decision to keep the alert level unchanged was therefore not significantly unreasonable, and was not illegal, the judge concluded.

On the responsibility of the Nagano Prefectural Government, which managed a seismometer at the volcano's summit, Tsutsui said that the prefecture could not be said to have had a specific obligation to hikers.

While offering condolences to the victims, the Meteorological Agency said it will work to enhance its volcano monitoring and assessments in an effort to release information accurately.