TOKYO, July 24 (Reuters) - A volcano on Japan's major western island of Kyushu erupted on Sunday evening (Jul 24), sending black smoke billowing high into the air, but there were no immediate reports of any damage or injuries, and authorities said they did not expect a major eruption.

The volcano, which is called Sakurajima and is located on the southern tip of Kyushu near the city of Kagoshima, erupted at about 8.05pm, the Japanese Meteorological Agency (JMA) said.

Volcanic stones rained down at a distance of 2.5km from the volcano, a JMA official said. The eruption alert level has been raised to 5, the highest, with some areas advised to evacuate, he added, but no large eruption was expected.

Sakurajima is one of Japan's most active volcanoes and eruptions of varying levels take place on a regular basis. In 2019 it spewed ash 5.5km high.

There were no immediate reports of damage from Sunday's eruption, deputy chief cabinet secretary Yoshihiko Isozaki told a news conference, as government officials sought more information on the situation.

Nuclear regulators said there were no irregularities detected at the Sendai atomic plant, which lies about 50km from the volcano.

Video footage showed what appeared to be a red mass flowing down one side of the volcano, with red projectiles shooting upwards.

The JMA said rain was expected in some areas near the volcano on Monday but not the kind of heavy rain that could cause mudslides following the eruption.

Most of the city of Kagoshima is across the bay from the volcano but several residential areas within about 3km of the crater may be ordered to evacuate depending on the situation, NHK said.

It later reported that 51 people in the vicinity were being evacuated.