A volcano on a southwestern Japan island erupted late Tuesday, sending large rocks nearly 1 kilometer from the crater, prompting the weather agency to raise its alert level.

The eruption occurred at the crater of Mt. Otake on Suwanose Island of Kagoshima Prefecture at 10:05 p.m. There were no immediate reports of injuries, according to local authorities.

Photo shows Suwanose Island of Kagoshima Prefecture on March 31, 2021. (Photo courtesy of the Japan Meteorological Agency)(Kyodo)

The Japan Meteorological Agency said early Wednesday that it has raised the volcanic activity alert level by one notch to 3 on a scale of 5, meaning that people should not approach the crater.

Following the eruption on Tuesday night, the volcano erupted again at 2:57 a.m. Wednesday, with large rocks projected nearly 1 km from the crater as before.

The agency warned of the potential for big rocks to be hurled into the air within about a 2-km radius of the crater.

Late last year amid intensifying volcanic activity, the agency raised its alert level to 3 on Dec. 28. It was lowered to level 2 on Jan. 14 in the absence of any major changes in volcanic activity data.

Supplied photo taken by a Japan Meteorological Agency camera shows an eruption at the crater of Mt. Otake on Suwanose Island of Kagoshima Prefecture on Dec. 28, 2020. (Kyodo)

Suwanose Island, a volcanic island with a small population, is located about 230 km south-southwest of Kagoshima.