Lumajang, East Java. At least 13 people were killed after the eruption of Mt Semeru that spewed hot ashes and lava and triggered mud floods in the East Java district of Lumajang, authorities said on Sunday.

The Saturday’s eruption also injured at least 50 villagers, who mostly suffered from burns, according to the National Disaster Mitigation Agency (BNPB).

"The search and rescue operations continue today," BNPB spokesman Abdul Muhari said.

Eight sand miners trapped by lava on the slope of the volcano were successfully evacuated on late Saturday, he added.

Torrential rain turned debris into mud flood that flattened homes in the village of Curah Kobokan. At least six villages were affected by the eruption, prompting more than 900 people to take refuge in nearby villages.

Photos from the scene showed homes and public facilities covered with ashes and volcanic debris.

The air pollution level in affected areas is classified as extremely harmful to human health.

Volcanic debris also destroyed several bridges and blocked access to some areas, hampering the evacuation efforts, Abdul said.

Mt Semeru, whose summit is 3,676 meters above sea level, erupted at around 14:30 local time on Saturday, spewing out incandescent lava and hot ashes to nearby villages.

The BNPB has sent two helicopters to the district to support evacuation works but visibility was very poor due to thick ashes blanketing the area.

Local authorities have declared a restricted zone within 5 kilometers from the crater.