People inspect buildings damaged by a flash flood in Agam, West Sumatra, Indonesia, on May 13, 2024.
| Photo Credit: AP

Rescuers on May 14 searched in rivers and the rubble of devastated villages for bodies, and whenever possible, survivors of flash floods that hit Indonesia’s Sumatra Island over the weekend.

Monsoon rains and a landslide of mud and cold lava from Mount Marapi caused rivers to breach their banks. The deluge tore through mountainside villages in four districts in West Sumatra province just before midnight Saturday.

Also read | Indonesia flood death toll rises to 41 with 17 missing

The floods swept away people and 79 homes and submerged hundreds of houses and buildings, forcing more than 3,300 residents to flee to temporary government shelters, National Disaster Management Agency spokesperson Abdul Muhari said.

Mr. Muhari said 50 bodies had been pulled from mud and rivers by Tuesday, mostly in worst-hit Agam and Tanah Datar districts, while rescuers are searching for 27 people who are reportedly missing.

Television reports showed rescue personnel using jackhammers, circular saws, farm tools and sometimes their bare hands, digging desperately in Agam district where roads were transformed into murky brown rivers and villages covered by thick mud, rocks, and uprooted trees.

Scores of rescue personnel were searching through a river around the Anai Valley Waterfall area in Tanah Datar district where tons of mud, rocks and trees were left from flash floods.

Rescuers were focused on finding four people from a group of seven that were swept away with their cars. Three other bodies were pulled out on Monday, said Abdul Malik, who heads the Search and Rescue Office in Padang, the provincial capital.

“With many missing and some remote areas still unreachable, the death toll was likely to rise,” Mr. Malik said.

Heavy rains cause frequent landslides and flash floods in Indonesia, an archipelago nation of more than 17,000 islands where millions of people live in mountainous areas or near floodplains.

The weekend disaster came just two months after heavy rains triggered flash floods and a landslide in West Sumatra, killing at least 26 people and leaving 11 others missing.

A surprise eruption of Mount Marapi late last year killed 23 climbers. The mountain’s sudden eruptions are difficult to predict because the source is shallow and near the peak, according to Indonesia’s Center for Volcanology and Geological Disaster Mitigation.

Marapi has been active since an eruption in January 2024 that caused no casualties. It is among more than 120 active volcanoes in Indonesia. The country is prone to seismic upheaval because of its location on the Pacific “Ring of Fire,” an arc of volcanoes and fault lines encircling the Pacific Basin.

Rescuers carry the body of a victim of a flash flood in Tanah Datar, West Sumatra, Indonesia, on May 13, 2024.
| Photo Credit: AP

The number of people killed by flash floods and cold lava flow from a volcano in western Indonesia over the weekend has risen to 41 with 17 more missing, a local disaster agency official told AFP, May 13.

Hours of heavy rain caused large volcanic rocks to roll down one of Indonesia’s most active volcanos into two districts on Sumatra island May 11 evening, while flooding inundated roads, homes and mosques.

“Data as of last night, we recorded 37 dead victims… But from this morning it has grown again, the figure reached 41 [dead],” Ilham Wahab, West Sumatra disaster mitigation agency official, told AFP.

Rescuers were searching for 17 still missing, three in Agam district and 14 in Tanah Datar, both the worst-hit areas of the flood and home to hundreds of thousands of people, he said.

Abdul Malik, head of the search and rescue agency in provincial capital Pandang, told reporters May 12 that the bodies retrieved included two children — a three-year-old and an eight-year-old.

Mr. Ilham encouraged “people to evacuate to relatives’ places, which are safer” than tent shelters in heavy rains. “We are focused on first, searching and rescuing the victims, second, protecting the evacuees, protecting the vulnerable people,” he said.

West Sumatra Governor Mahyeldi Ansharullah told reporters on May 13 that around 130 people had evacuated to an elementary school in Agam, while more than 2,000 people were evacuated to several places in Tanah Datar. Roads in the districts were turned into rivers, with mosques and houses damaged.

Heavy rains inundated neighbourhoods with muddy flood waters and swept vehicles into a nearby river, while volcanic ash and large rocks rumbled down Mount Marapi.

Cold lava, also known as lahar, is volcanic material such as ash, sand and pebbles carried down a volcano’s slopes by rain.

Survivors recounted their horror

Authorities sent a team of rescuers and rubber boats to look for the missing victims and to transport people to shelters.

The local government set up evacuation centres and emergency posts in several areas of Agam and Tanah Datar.

The national disaster mitigation agency, or BNPB, said 84 homes, 16 bridges and two mosques were damaged in Tanah Datar, as were 20 hectares (50 acres) of rice fields.

Survivors recounted their horror when the flooding and rockfall began.

“I heard the thunder and the sound similar to boiling water. It was the sound of big rocks falling,” housewife Rina Devina told AFP, adding that three of her neighbours were killed. “It was pitch black, so I used my cellphone as a flashlight. The road was muddy, so I chanted ‘God, have mercy!’ over and over again,” she said of her evacuation to a local official’s office.

Dwikorita Karnawati, head of Indonesia’s meteorology, climatology and geophysics Agency (BMKG), told reporters May 13 that West Sumatra was a “unique location” because in parts of the province, rain could fall almost all year round. “So the potential for flood and landslide are always present,” she said.

Indonesia is prone to landslides and floods during the rainy season.

In 2022, about 24,000 people were evacuated and two children were killed in floods on Sumatra island, with environmental campaigners blaming deforestation caused by logging for worsening the disaster.

Trees act as natural defences against floods, slowing the rate at which water runs down hills and into rivers.

Marapi’s last major eruption took place in December and spewed an ash tower about 3,000 metres into the sky, taller than the volcano itself. At least 24 climbers, most of them university students, died in the eruption.