People move their belongings after dwellings built near the main landfill of Addis Ababa, Ethi­o­pia, on the outskirts of the city were damaged in a landslide that killed at dozens of people. (Zacharias Abubeker/AFP via Getty Images)

A mountain of trash gave way in a massive garbage dump on the outskirts of Ethiopia’s capital, killing at least 46 people and leaving several dozen missing, residents said, as officials vowed to relocate those who called the landfill home.

Addis Ababa city spokeswoman Dagmawit Moges said most of the 46 dead were women and children, and more bodies were expected to be found.

It was not clear what caused Saturday night’s collapse at the Koshe Garbage Landfill, which buried makeshift houses and concrete buildings. The landfill has been a dumping ground for the capital’s garbage for more than 50 years.

About 150 people were there when the landslide occurred, resident Assefa Teklemahimanot said. Mayor Diriba Kuma said 37 people had been rescued and were receiving medical treatment.

Many people at the landfill had been scavenging items to make a living, but others live there because renting homes, largely built of mud and sticks, is relatively inexpensive.

“My house was right inside there,” said a shaken Tebeju Asres, pointing to where one of six excavators was digging in deep, black mud. “My mother and three of my sisters were there when the landslide happened. Now I don’t know the fate of all of them.”

The resumption of garbage dumping at the site in recent months probably caused the landslide, Assefa said. The dumping had stopped in recent years, but it resumed after farmers in a nearby restive region where a new garbage landfill complex was being built blocked dumping in their area.

Smaller collapses have occurred at Koshe in the past two years but only two or three people were killed, Assefa said.

About 500 waste-pickers are thought to work at the landfill every day, sorting through the debris from the capital’s estimated 4 million residents. City officials say close to 300,000 tons of waste are collected each year, most of it dumped at the landfill.

Since 2010, city officials have warned that the landfill was running out of room and was being closed in by nearby housing and schools.

City officials in recent years have been trying to turn the garbage into a source of clean energy with a $120 million investment. The Koshe waste-to-energy facility, under construction since 2013, is expected to generate 50 megawatts of electricity on completion.

Ethiopia, one of Africa’s fastest-growing economies, is under a state of emergency imposed in October after months of protests for wider political freedoms.