Indonesia’s Mount Merapi erupted on Saturday with avalanches of lava and clouds of fiery gas, forcing authorities to halt tourism and mining activities on the slopes of the country’s most active volcano.

Merapi, on the densely populated island of Java, unleashed clouds of hot ash and a mixture of rock, lava and gas that traveled up to 4.3 miles down its slopes. A column of hot clouds rose 100 yards into the air, National Disaster Management Agency spokesman Abdul Muhari said.

The eruption throughout the day blocked out the sun and covered several villages with falling ash. No casualties have been reported.

It was the largest lava flow from Merapi since authorities raised the alert level to the second highest in November 2020, said Hanik Humaida, director of the Yogyakarta Center for Volcanology and Geological Hazard Mitigation.

She said residents living on the slopes of Merapi were advised to stay 4.3 miles away from the crater mouth and to be aware of the danger posed by lava.

Tourism and mining activities were paralyzed.

The 9,737-foot mountain is about 18 miles from Yogyakarta, an ancient center of Javanese culture and seat of royal dynasties dating back centuries. About a quarter of a million people live within 6 miles of the volcano.

Merapi is the most active of more than 120 active volcanoes in Indonesia and has recently erupted repeatedly with clouds of lava and gas. Its last major eruption in 2010 killed 347 people and displaced 20,000 villagers.

Indonesia, an archipelago of 270 million people, is prone to earthquakes and volcanic activity because it sits along the «Ring of Fire,» a series of horseshoe-shaped seismic fault lines around the Pacific Ocean.

A December 2021 eruption of Mount Semeru, the highest volcano on the island of Java, left 48 dead and 36 missing.