A volcano located on a mountain range on the island of Kyushu, southwest Japan, erupted for the second time Tuesday in an explosion local officials said was five times bigger than the one last Wednesday.
The eruption sent an enormous plume of gas, ash and rocks shooting as high as 2,000 meters into the air and the blast smashed windows in hotels and offices as far away as eight kilometers, local reports said.
As yet no deaths have been reported as a result of the eruption, although one women was cut by shattered glass and felled trees caused by the blast have been hindering traffic in the region, local officials said.
Following the latest blast, the Japan Meteorological Agency raised the alert level from two to three, on a scale of one to five, and extended a no-go zone around the 1420-meter-high peak of Shinmoedake volcano to four kilometers.
The volcano, one of 108 active volcanoes in Japan, comprises the Kirishima mountain range on the island of Kyushu and more than 1,000 residents of the town of Takaharu in Miyazaki Prefecture, close to the peak, have been forced to evacuate and take shelter in local school halls and community facilities.
Local media reported however that as the evacuation was advisory and not mandatory some residents have returned to their homes despite experts saying bigger, more devastating eruptions may be imminent.
Japanese volcanologists have deduced that molten lava is building up in the crater as a result of subterranean pressure and there is speculation as to whether another blast could send the lava cascading down the side of the mountain.
Officials from the meteorological agency noted that the dome of lava inside the volcano had expanded to five times the size it was last Friday.
It is the volcano's first major eruption in 52 years and clouds of smoke and ash have caused major disruption to flights, train and other public transportation in the region.
Local school have also been closed and people in the area have been advised to protect themselves against superheated noxious gases, ash and smoke with face masks, umbrellas and sunglasses.
Japan's southern islands fall within the seismically active zone dubbed the Pacific "Ring of Fire," and in 1991, 43 people died in the eruption of Mount Unzen, also located on Kyushu island.
Japan's iconic Mount Fuji, the tallest mountain in the country, is in fact itself an active volcano, but falls into a low-risk category, according to the meteorological agency. In December 1707 Mount Fuji blew its top in a colossal eruption that continued for more than two weeks.
The Japan Meteorological Agency defines volcanoes that have erupted in the last 10,000 years or have fumarolic activity as active volcanoes.