(NTV) Scientists in Japan say another volcano is showing signs of being ready to erupt.

Mt. Kirishima on Japan’s western Kyushu Island last erupted in 2011.

Authorities say 158 tremors registered Tuesday at the Shinmoe Peak.

Experts from Japan’s meteorological agency surveyed the peak’s surface temperature and other data Wednesday, but detected no abnormalities.

Still, they said a small eruption is possible and kept the warning level at 2. That means hikers must act with caution when approaching within half-a-mile of the caldera.

Copyright NBC News 2016