Japan volcano Sakurajima erupts spectacularly as lightning flashes in the sky

One of Japan's most active volcanoes has erupted spectacularly with a fiery blast sending lava rolling down its slopes, while lightning-like flashes fizzed in the sky.

The orange burst was captured on camera as dark grey smoke and ash travelled up to 2km after billowing out of the side of Sakurajima, close to the summit on the southern island of Kyushu.

Rocks spewing out of the crater were expected to fall within a 2km no-go zone set up by officials. There were no immediate reports of injuries.

"I don't think there will be any serious impact from the explosion," Kyoto University volcanologist Kazuhiro Ishihara said. "But of course we must keep monitoring the volcanic activity."

While dramatic, the blast was average compared with Sakurajima's past eruptions, the most recent of which was in September.

Sakurajima, a mountain on the southern island of Kyushu, is one of Japan's most active volcanoes. Credit: Reuters/Kyodo

The Japanese archipelago is in the Pacific Ring of Fire, an arc of volcanoes and fault lines in the Pacific Basin which has more than 100 volcanoes.

The 2014 eruption of Mount Ontake in central Japan killed 57 people.