Neighbourhood leader Lancine Sylla had earlier told the AFP news agency that he feared there would be a heavy death toll.
“We have pulled out 18 bodies that were taken to the morgue,” he said.
Visiting the injured in hospital, Health Minister Khaïté Sall said they would get free medical care, while assuring families of government support.
Guinea has experienced similar landslide tragedies before, with 10 people being killed at the same site in 2017.
The government had recently ordered people living close to the site to move, but many residents chose to stay.
Guinea’s opposition figure and former Prime Minister Cellou Dalein Diallo, who is in exile abroad, called the accident “a tragedy that plunges us into dismay”.
“This tragedy is all the more worrying because the closure of the landfill had been announced for this Sunday, 23 August”, he said.
Rescue teams are continuing to search through the waste for others trapped underneath.
