Four people from the German consulting group Tüv Süd, company that certified the safety of Vale’s dams, were also detained.
All of the Vale employees arrested, which included two executives, were responsible for the security and stability of the Brumadinho dam and will remain in prison for 30 days, GloboNews TV channel reported.
It follows the arrest of five people last month, including three employees and two other engineers working on behalf of the company, deepening a crisis for the company after another deadly disaster at one of its mines.
Brazilian police were also carrying out 14 search warrants to seize documents and other potentially useful material as part of the probe.
Earlier this month, an internal report quoted by Brazilian paper Folha de S.Paulo showed Vale knew the dam was at risk as it was told the site breached guidelines months before it collapsed.
Vale, which is the world's top iron ore miner, said the report was misleading as there was no evidence of imminent risk.
The collapse of the Feijão dam is the second major mining disaster in in the state of Minas Gerais since 2015, when a tailings storage facility burst at Samarco — a joint venture between Vale and BHP — killing 19 people and becoming Brazil's worst environmental disaster.