Japan Meteorological Agency (JMA) said, Sakurajima volcano in southwestern Japan located near the Sendai nuclear power plant erupted on a small scale early on Wednesday.
The eruption occurred at 3:13am and was the first one to be observed at the 1,117-meter volcano since JMA increased alert level 3 to a level 4 on Saturday, more than 1,000 earthquakes registered near the volcano.
The agency reported that after the recent eruption, it also observed a phenomenon called volcanic glow, in which air above the crater looks red due to the reflection of magma and red-hot volcanic rocks.
Earlier, 71 residents located in the area were advised to evacuate the region.
Since a major eruption could occur, local authorities stated that 4,500 other people who live near the area may have to be evacuated.
After 2011 Fukushima nuclear disaster, in which the nuclear plant was hit by a 46-foot tsunami, destroying three of the six reactors and killing thousands of people, new safety rules were introduced in Japan.
Earlier this month, Sendai nuclear power plant, became the first nuclear facility to restart one of its reactors following these new rules. Facility is located some 50 km from the Sakurajima volcano.
The Sakurajima volcano, in Kagoshima Prefecture, was reported to have had more than 1,000 eruptions since the beginning of this year and the latest was one of the smallest.