Mount Sakurajima in Kagoshima Prefecture may erupt on a large scale, given recent data analysis, a weather agency panel has said.

The frequency of eruptions at Minamidake summit crater 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 forecasting volcanic activities at the Meteorological Agency said Tuesday.

The panel maintained 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 they thought the volcano was likely to erupt.

On May 9, a plume of ash spewed from the 1,040-meter Minamidake summit crater in an eruption that reached about 4,200 meters into 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 thrown onto the upper part of the mountain and volcanic ash fell in nearby municipalities. Six flights to and from Kagoshima Airport were also cancelled due to ash.