CAIRO (AP) — The deadly mountain landslide in Sudan’s western region of Darfur over the weekend killed as many as 200 children, a prominent aid group said Friday, with rescue operations in the area still underway.

More than 1,000 people, many of them buried in mud, are believed to have lost their lives in the Aug. 31 landslide. Save the Children said 150 people, including 40 children, survived and were receiving medical treatment.

“This is a tragedy (within) a tragedy that is the current conflict in Sudan. This is one of the worst natural disasters that has happened in Sudan,” Save the Children’s operations director for Sudan, Francesco Lanino, told The Associated Press on Friday.

Sudan is was already experiencing one of the worst humanitarian crises in the world caused by the civil war that erupted in April 2023 in the capital Khartoum. The conflict spread across the country after simmering tensions escalated between the Sudanese army and its rival paramilitary Rapid Support Forces. More than 40,000 people have been killed and as many as 12 million displaced.

Sudanese authorities recovered on Thursday the bodies of 375 people who died in the Aug. 31 landslide that followed days of heavy rains in the village of Tarasin in the Marrah Mountains.

The landslide killed as many as 1,000 people, Mohamed Abdel-Rahman al-Nair, a spokesperson for the Sudan Liberation Movement Army, has said. The United Nations’ Office for the Coordination of Humanitarian Affairs had a similar death toll estimate but said it’s hard to confirm the magnitude of the tragedy because the area is hard to reach.

“Think about a village with all its existing schools and health facilities totally under the mud, and half of the mountain collapsed all over the village which is fully covered so there is nothing left of the existing structure,” Lanino said.

Lanino said his team arrived at Tarasin and its surrounding areas on Friday after heading out Thursday morning using donkeys due to the rough terrain and destroyed roads in areas of Darfur affected by heavy rains. He added that the village is outside of any cellular phone network or any other way to communicate with the outside world.

Lanino said the team was shocked to see that almost half of the mountain had collapsed on the village at its bottom. He said the landslide involved at least two waves with the first starting Sunday afternoon, according to survivors who spoke with the group. A few hours later came the second wave, which hit nearby villages and victimized villagers who had been helping people hit by the initial wave.

Lanino estimated that thousands are missing as the number of people still trapped under the mud is unclear. Survivors counted by Save the Children are now receiving medical and protection support from the aid group.

Residents and local authorities still fear another landslide because there is still heavy rain.

“People living by Tarasin they’re saying it’s still raining, that ’we can somehow hear the sound of the mountains cracking’ and they are really worried that more landslides might come,” said Lanino.

This prompted people to move to nearby villages around 5 kilometers (3 miles) from the main center of the tragedy, but they still lack food, clean water, medical supplies, shelter and the ability to move to further safer locations that are away from the bottom of the mountains.

Save the Children and other aid groups are delivering aid to affected people and helping facilitate their relocation to safer areas by camel and donkey.