The volcano has been under an orange alert since September
Japan's Sakurajima volcano, located just 50kms from a nuclear plant, has erupted sending lava flowing down its slope and spewing into the night sky.
Local television showed dramatic pictures of the fiery spectacle.
Japan's meteorological agency said the eruption happened at 6.56pm local time (9.56am Irish time).
"It appears that stones have been thrown about 2kms from the crater, but this area is quite far from any communities," said Kazuhiro Ishihara, a professor at Kyoto University.
The volcano, in the southern Kagoshima prefecture, has been showing increased activity since August when locals were told to prepare for a larger than usual eruption and possible evacuation.
An eruption in 1914 was the most powerful in Japan in the twentieth century, with lava flows permanently connecting the former island volcano to the Kyushu mainland.
The Sendai nuclear plant is only 50kms away but so far has not issued any warnings.
Japan has more than 100 active volcanoes and lies on the 'Ring of Fire' - a horseshoe-shaped band of fault lines and volcanoes around the edge of the Pacific.
Footage shows the full extent of the eruption: