Mount Ontake, a volcano that spontaneously erupted in Japan on Saturday, has left dozens of hikers presumed dead near its peak, a spokesperson for the Japanese police said. The mountain continues to spew dangerous smoke, making rescue efforts difficult.

The New York Times reports that 31 hikers were discovered by the peak of the mountain, though officials were reluctant to declare the hikers dead until confirmed by doctors.

Via the New York Times:

The spokesman, Naofumi Miyairi, said that a perfunctory check by rescuers on the mountain indicated that their hearts and lungs appeared to have stopped, making it all but certain that they were dead. Mr. Miyairi said rescuers had found the fallen hikers near the top of Mount Ontake, a 10,062-foot volcano that erupted in a spectacular geyser of ash on Saturday, when the mountain was busy with climbers who had gone to see the first signs of autumn.

Helicopters were finally able to break through the thick ash on Sunday morning to assist in rescue efforts, and a number of hikers had hidden in shelters to avoid being hurt in the explosion.

According to reports, there could have been at least 250 hikers on Mount Ontake at the time of its eruption.

[Image via AP]