The victims had gathered at the top of a hill for a memorial service for five people when the ground collapsed under part of the audience.
“Some were sitting in a tent where there was a landslide early this evening,” Paul Bea, governor of the Centre region that includes Yaounde, told state radio.
He added that rescue efforts were ongoing.
The search had been suspended late Sunday evening before a planned resumption on Monday morning, a rescue worker at the scene told AFP.
Marie Claire Mendouga, 50, attended the ceremony but her tent was not affected by the landslide.
“We had just started to dance when the ground collapsed,” she told AFP.
She said she “went to dig with my hands” to try to get people out from under the earth, and was still covered in the brown clay from the site.
– Frantic search –The disaster took place in Yaounde’s working-class district of Damas, on its eastern outskirts.
Four large white tents were on the hill’s summit, at the edge of what seemed to be a ridge, beyond which the ground had disappeared, an AFP correspondent at the scene said.
Police pick-up trucks were hauling away bodies covered by white sheets early on Sunday evening.
A police cordon prevented journalists from getting closer to the scene.
Emergency services struggled to make their way to the site, as hundreds of people frantically searched for loved ones.
Some in the crowd wept as emergency workers scoured the area.
By 10:00 pm (2100 GMT) the search had been called off.
A member of the emergency services who asked not to be named said the death toll remained at 11, and the search for more victims would resume Monday morning.
In the crowd behind the security cordon, tears were streaming down faces.
“I’m not sure if I’ll be able to sleep,” Mendouga said.
“You are sitting down, you have people behind you and afterwards, they’re dead.
Landslides occur relatively frequently in Cameroon, but they are rarely as deadly as Sunday’s incident in Yaounde.
Forty-three people were killed in the western city of Bafoussam in 2019, when a landslide triggered by heavy rains swept away a dozen precarious dwellings built on the side of a hill.