The death toll from a landslide at a vast garbage dump in Uganda's capital of Kampala has risen to 21, police said on Sunday, as rescue workers continued to dig for survivors.

After torrential rain in recent weeks, a huge mound of garbage at the city's only landfill site collapsed late on Friday, crushing and burying homes on the edge of the site as residents slept.

Ugandan President Yoweri Museveni said in a statement he had directed the prime minister to co-ordinate the removal of all those living near the garbage dump.

The government has also started investigations into the landslide's cause and will take action against any officials found to have been negligent, the Inspectorate of Government said on the social media platform X.

At least 14 people have been rescued so far, police spokesperson Patrick Onyango said, adding that more could still be trapped but the number was unknown.

Tents have been set up nearby for those displaced by the landslide, the Red Cross said.

The landfill site, known as Kiteezi, has served as Kampala's sole garbage dump for decades and had turned into a big hill. Residents have long complained of hazardous waste polluting the environment and posing a danger to residents.

Efforts by the city authority to procure a new landfill site have dragged on for years.

There have been similar tragedies elsewhere in Africa from poorly managed mountains of municipal garbage.

In 2017, at least 115 people were killed in Ethiopia, crushed by a garbage landslide in Addis Ababa. In Mozambique, at least 17 people died in a similar 2018 disaster in Maputo.