Japan's Sakurajima volcano has erupted again and belched a massive column of ash almost a mile into the sky. Locals posted photos and video clips on social media as one of the most active volcanoes in the world erupted at about 4 pm local time. Sakurajima, which translates into "cherry blossom island", has erupted a number of times this month and officers have warned the public of volcanic ash. The volcano - about five miles from a city with half a million residents and 30 miles from a nuclear power plant - was once an island but lava flows turned it into a peninsula in southern Kyushu in 1914. It is one of few in the world that is in constant activity and is therefore considered a very dangerous volcano. During Friday's eruption, the ash column extended almost a mile into the sky, according to Japan's meteorological agency. A volcanic ash advisory has been issued. There have been a number of eruptions at Sakurajima - set on a peninsula of the same name - this month. The current warning level is three out of five, meaning "minor volcanic eruption". There has been a number of major eruptions over the years. Volcanic lightning was seen at an eruption of Sakurajima in February 2016. In that event, fountains of lava shot into the night sky. Sakurajima is one of the most active volcanoes in the world and one of the few that are at present in constant activity, according to Volcano Discovery. It is about five miles from the city of Kagoshima, which is home to half a million people. Eruptions have been recorded as far back as the 8th century and it had frequently dropped ash on Kagoshima.