Mt. Sakurajima in southwestern Japan may erupt on a large scale, given recent data analysis, a weather agency panel said Tuesday.

The frequency of eruptions at Minamidake summit crater in Kagoshima Prefecture has been on the decrease while the volume of volcanic ashes remains unchanged, meaning the upcoming eruption could be bigger than usual, the panel on forecast of volcanic activities at the Japan Meteorological Agency said.

Photo taken Nov. 8, 2019, from an unmanned fixed-point camera in Tarumizu, southwestern Japan, shows an eruption on Mt. Sakurajima in Kagoshima Prefecture. (Kyodo) 

The panel maintains its alert for the active volcano at level 3, warning not to approach the crater. A local weather observatory warns of a small-scale pyroclastic flow when the volcano erupts.

On Sakurajima, a mountainous island in Kagoshima Bay with one side connecting the main island of Kyushu, bloating and lifting of the mountain as well as crustal movement have been observed since around last September, the panel said.

The panel did not say specifically when the volcano is likely to erupt.

On May 9, plume of ash spewed from the volcano's 1,040-meter Minamidake summit crater in the eruption, reaching about 4,200 meters in the sky. The volcano also made a similar-size eruption on Nov. 8.

While no damage was reported by the last eruption, large rocks were flown to the upper part of the mountain and volcanic ashes were falling in nearby municipalities. Six flights to and from Kagoshima airport were also cancelled due to ashes.

Photo taken May 9, 2020, from an unmanned fixed-point camera in Tarumizu, southwestern Japan, shows an eruption on Mt. Sakurajima in Kagoshima Prefecture. (Kyodo)