According to the Kyodo news agency, Japan issued an alarm on Friday after a volcano in the country's southwest erupted, hurling big rocks hundreds of meters out from the crater.
According to Kyodo, there were no early reports of injuries following the eruption of Mount Otake in Kagoshima prefecture.
After the eruption about 2:00 a.m., the Japan Meteorological Agency raised the alert level to three on a scale of five, with five triggering evacuation and restricting access to the area around the mountain (1700 GMT Thursday).
Several early "explosions" "According to the agency, which Kyodo cited, an incident occurred at the crater on Thursday.
According to the agency, large rocks launched from the volcano might land within a two-kilometer (1.2-mile) radius.
In March, Mount Otake erupted similarly, prompting the meteorological agency to issue a level-three alert.
Japan is located on the Pacific "Ring of Fire," which is home to several active volcanoes, "which records a high percentage of the world's earthquakes and volcanic eruptions.