The official death toll from a dam burst in the Brazilian town of Brumadinho rose to 169, authorities in the state of Minas Gerais said on Monday.
In addition, 141 people have yet to be located, authorities say.
The dam, which held back mining byproducts, is owned by nickel and iron ore miner Vale SA.
About 200 residents were evacuated from an area near another tailings dam operated by Vale on Saturday, amid fears that it was structurally weak and could also collapse.
A dam is a barrier that stops or restricts the flow of water or underground streams.
Reservoirs created by dams not only suppress floods, they also provide water for activities such as irrigation, human consumption, industrial use, aquaculture and navigability.