Indonesia's National Board for Disaster Management (BNPB) said in a statement Sunday the eruption had wounded 98 others, including two pregnant women after it covered villages with ash and left people to run from billowing clouds of debris, CNN reported.
At least 300 families were evacuated following the eruption, according to Indah Amperawati, deputy head of Lumajang District, an area close to the volcano.
In its statement Sunday, the BNPB said search and rescue efforts were ongoing but did not specify the number of people who were still reported missing.
Authorities have converted schools, mosques, village halls and village houses into evacuation centers, the statement said.
Java is the largest population center in Indonesia's massive island archipelago and home to the capital city of Jakarta. Standing at more than 12,000 feet high, Mount Semeru is the tallest mountain on Java.
Lumajang District deputy head Indah said that most of the burn victims have been evacuated to the Penanggal Primarily Health Center alongside a resident who died in the village of Curah Kobokan.
Emergency services have been unable to reach several other villages due to roads being blocked by mud and fallen trees, Indah told the press conference.
The military has been asked for people and equipment to support rescue efforts, Maj. Gen. TNI Suharyanto, the head of the BNPB, told the press conference.
Budi Santosa, head of disaster management of East Java province, said earlier on Saturday that two sub-districts had been "badly affected" by the volcano's eruption.
Volcanic ash and the smell of sulfur was first reported around 3 p.m. local time (3 a.m. ET), according to the Mount Semeru Volcano Observation Post. The station added that hot ash clouds were falling towards an East Java village, Sapitarang, in Pronojiwo District.
ZZ/PR