TOKYO: A volcano in southern Japan dramatically erupted Friday, with television footage showing fiery hot lava flowing down its slopes and smoke rising skyward.

The Japan Meteorological Agency said on its website that Sakurajima in southern Kagoshima prefecture erupted at 6:56 pm (0956 GMT). There were no immediate reports of damage or injuries.

The eruption shot out large rocks, with the agency warning debris and pyroclastic flows - super hot and fast-moving mixture of gases and rock fragments - could reach as far as two kilometres (1.25 miles) away from the eruption vents. But it did not affect the operation of the closest nuclear reactors, sitting some 50 kilometres (31 miles) from the mountain, but highlighted concerns among activists, media reports quoted operator Kyushu Electric as saying. The weather agency raised the 1,117-metre (3,665-foot) volcano's alert status to Level 3, which bans entry onto the mountain, from Level 2, which limited people from going near the vents. The elevated level, however, stopped short of urging local residents to prepare for possible evacuation, according to the agency.–AFP

Local police have received no immediate report of damage on the peninsula of Sakurajima, where the volcano is located, which has a population of about 4,000 people.

The volcano sits about 12 kilometres across a bay from the main part of the city of Kagoshima, with a population of more than 600,000 people, on the southern main island of Kyushu.

The volcano frequently spits out smoke and ash and is a major tourist attraction and one of Japan's most famous sites.

A volcano expert told NHK that the eruption happened away from residential areas, and did not expect it to have a significant impact. But it highlighted concerns that the volcano could affect nuclear reactors some 50 kilometres away, according to campaign group Greenpeace.

Kyushu Electric conducted "flawed volcano risk analysis" that "underestimated the potential impacts of ash deposits on operations of the Sendai nuclear reactors following a major volcanic eruption," Greenpeace said in a statement, released shortly after the latest eruption.

Sakurajima last went through a major eruption in 2013, spewing an ash plume up to 5,000 metres into the air, causing damage but no major injuries.

There are scores of active volcanoes in Japan, which sits on the so-called "Ring of Fire", where a large proportion of the world's quakes and eruptions are recorded.

In September 2014, Mount Ontake in central Nagano prefecture violently erupted, leaving 58 people dead and five others missing in the nation's deadliest eruption for almost 90 years.