A volcano in western Indonesian unleashed hot clouds of ash on Saturday, killing three villagers and injuring four others, an official said. Mount Sinabung in North Sumatra province blasted volcanic ash as high as 3 kilometers (2 miles) into the sky, said National Disaster Management Agency spokesman Sutopo Purwo Nugroho. He said ash tumbled down the slopes as far as 4.5 kilometers (3 miles) westward into a river. The 2,600-meter (8,530-foot) -high mountain in Karo District had been dormant for four centuries before springing to life in August 2010, killing two people and forcing 30,000 to flee. An eruption in February 2014 killed 16 people. All the victims of Saturday's eruption were working on their farms in the village of Gamber in Simpang Empat subdistrict, about 4 kilometers (2.5 miles) away from the slope, or within the danger area. Mount Sinabung is among more than 120 active volcanoes in Indonesia, which is prone to seismic upheaval due to its location on the Pacific "Ring of Fire," an arc of volcanoes and fault lines encircling the Pacific Basin.