A thick layer of ash covered several villages up to 20km from the crater, said Armen Putra, an official at the Mount Sinabung observation post.
The volcano, one of two currently erupting in Indonesia, had been dormant for four centuries before erupting in 2010, killing two people. Another eruption in 2014 killed 16 people, while seven died in a 2016 eruption.
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.
🌋 #Indonesia 🇮🇩 La explosión del #Sinabung alcanzó una altura aproximadamente de 5 km sobre la cima, está acompañado por un flujo piroclástico que se desarrolló en unos de sus flancos.
Ya hay reportes de caída de cenizas en zonas aledañas al macizo.