Flash floods and a cold lava flow hit the Indonesian island of Sumatra, killing at least 15 people.

PADANG, Indonesia (AP) — Heavy rain and torrents of cold lava and mud flowing down the slopes of a volcano on the Indonesian island of Sumatra triggered flash floods that killed at least 15 people and injured others several more, officials said Sunday.

Monsoon rains and a large mudslide caused by a cold lava flow on Mount Marapi caused a river to burst its banks and flow through mountainside villages in Agam and Tanah Datar districts, in West Sumatra province, shortly before midnight on Saturday. The floods swept away people and submerged more than 100 homes and buildings, said Abdul Muhari, a spokesman for the National Disaster Management Agency.

Cold lava, also known as lahar, is a mixture of volcanic material and pebbles that flows down the slopes of a volcano in the rain.

By Sunday, rescuers had removed 11 bodies from the worst-hit village of Canduang and recovered four more bodies from the neighboring village of Sungai Pua, Muhari said.

The agency said in a statement that at least seven villagers were injured by the flash floods and that rescuers were searching for other possible victims. According to the statement, 60 people fled to temporary government shelters.

The disaster came just two months after heavy rains triggered flash floods and a landslide in West Sumatra’s Pesisir Selatan and Padang Pariaman districts, killing at least 21 people and leaving five others untouched disappeared.

Mount Marapi, peaking at 2,885 meters (9,465 feet), erupted late last year, killing 23 climbers who were surprised by a surprise weekend eruption. The volcano has remained at the third highest alert level of four since 2011, indicating above-normal volcanic activity under which climbers and villagers should stay more than 3 kilometers (1.8 miles) from the summit, according to the Indonesian Center for Volcanology and Geological Disaster Mitigation. .

Marapi is known for sudden eruptions that are difficult to predict because the source is shallow and close to the summit, and its eruptions are not caused by deep movement of magma, which triggers tremors recorded on seismic monitors.

Marapi has been active since an eruption in January 2023 which caused no casualties. It is one of more than 120 active volcanoes in Indonesia, prone to earthquakes due to its location on the Pacific “Ring of Fire,” an arc of volcanoes and fault lines encircling the Pacific basin.