No casualties have been reported so far, and emergency services are still assessing the situation on the ground while gathering information on possible victims and displaced people, Budi Santosa, head of disaster management in East Java province, said on live television on Saturday.
He said there are two sub-districts that have been “badly affected” by the eruption of the volcano.
Volcanic ash, the smell of sulfur was reported around noon. 15 local time (03:00 ET), Mount Semeru Volcano Observation Post reported. It added that hot ash clouds were falling towards an East Java village, Sapitarang, in the Pronojiwo district.
Videos shared by the government emergency team showed residents in the area running away from huge thick clouds of smoke.
Other footage shared by locals showed people gathering at a local mosque in Besuk Kobokan, while ash and smoke cover the surrounding streets.
Santosa told the news conference that he believed that health facilities in the disaster area, either primary health centers or hospitals, would be able to accommodate any victims.
His team is currently trying to carry out evacuations and prepare refugee camps in the area that will provide food, masks, blankets and shelter to displaced residents.
Indonesia sits between two continental plates on what is known as the Ring of Fire, a band around the Pacific basin that leads to high levels of tectonic and volcanic activity.