The resignations came after documents emerged in recent weeks showing that Vale knew it had an elevated risk of rupture and that inspectors felt they were under pressure to certify the structure as safe.

Three years after the 2015 dam rupture in Mariana that killed 19 people, industry regulations have gotten less, not more, rigorous in Minas Gerais state.

The Brazil dam collapse left as many as 115 people dead, according to the most recent count.

Brazilian officials on Sunday resumed the search for hundreds of missing people in the wake of a massive dam collapse.

A dam belonging to miner Vale SA ruptured on Friday in Brazil, pouring out mud into the surrounding area and leading local residents to be evacuated.