Japan’s largest active volcano, Mount Aso, erupted Monday, prompting the Japan Meteorological Agency (JMA) to raise its five-scale volcanic alert level to three from two, warning people not to approach the area. The eruption shot plumes of smoke 2,000 meters (6,560 feet) into the air.

Mount Aso, located on the southern Japanese island of Kyushu, erupted at 9.43 a.m. JST (8:43 EDT), the Meteorological Agency said. Local officials evacuated about 30 tourists and shop workers from the area, Agence France-Presse (AFP) reported. No injuries or casualties were recorded.

"We suddenly saw an unusually massive plume rising in the air," Kimihiko Jo, an Aso official, told AFP. "The black and grey column at one point appeared to be weakening, but it's growing bigger again."

Troops, police and firefighters were deployed in the area to examine any damage following the eruption, Prime Minister Shinzo Abe reportedly said in Tokyo. At least 18 domestic flights were reportedly cancelled, while some flights to the nearby city of Kumamoto were diverted due to the volcanic ash. The JMA said the eruption shot bits of volcanic rock, smoke and steam into the air and it remained unclear if it caused any volcanic flow from the mountain, the Associated Press reported.

Authorities did not rule out a second eruption, Sadayuki Kitagawa, senior coordinator for volcanic affairs at the JMA, said, according to RT.com. Kitagawa cautioned people to be careful of falling rocks due to a “possibility of volcanic rocks landing in an area over a 1-kilometer (over half a mile) radius.”

Nuclear plants, including the Sendai nuclear plant that resumed operations in August following the Fukushima Daiichi nuclear disaster, were not affected by the eruption, Kyushu Electric Power Co. reportedly said. Sendai nuclear plant is located about 100 miles south of Mount Aso.

The 5,253-feet Mount Aso caught the attention of authorities last August when it recorded smaller levels of eruptions and last week, Aso experienced a series of small eruptions. However, Monday’s eruption was bigger than the past events.

Japan, one of the world’s most volcanically active countries, is located on top of the Pacific "ring of fire" -- an unstable tectonic zone -- and has more than 100 volcanoes. In June, search teams returned to the Mount Ontake peak in central Nagano prefecture to look for the bodies of six climbers who are still missing following an eruption last September that killed 57 people.