Flash floods and cold lava flows have hit the Indonesian island of Sumatra, killing at least 15 people

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

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

Cold lava, also called lahar, is a mixture of volcanic material and pebbles that flows down the slopes of a volcano when it rains.

As of Sunday, rescuers had recovered 11 bodies from the worst-hit village of Canduang and four more bodies in 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 rescuers were searching for other possible victims. It said 60 people had fled to temporary government shelters.

The disaster came just two months after heavy rains triggered flash floods and a landslide in the Pesisir Selatan and Padang Pariaman districts of West Sumatra, leaving at least 21 people dead and five others missing.

The 2,885-meter-high Mount Marapi erupted late last year, killing 23 climbers in a surprise eruption over the weekend. According to the Indonesian Center for Volcanology and Geological Disaster Risk Reduction, the volcano has been at the third highest of four alert levels since 2011, indicating above-average volcanic activity that requires climbers and villagers to stay more than three kilometers (1.8 miles) from the summit .

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 magma movement that triggers tremors that register on seismic monitors.

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