RIO DE JANEIRO – The toll from a dam collapse at a mine in southeast Brazil’s Minas Gerais state has risen to 157 deaths after nearly two weeks of searches, with 182 missing, authorities said Thurday.

Those listed as missing are presumed dead, but not yet located under the layers of muddy mining waste released when the tailings dam broke apart in the town of Brumadinho on January 25, burying entire neighborhoods in the town under meters of toxic mud.

A total of 192 people were rescued alive, said Flavio Godinho, spokesman for the Minas Gerais state civil defense agency.

More than 400 rescue workers were continuing to slog through the mud in search of victims, though there were little hope of finding survivors at the moment. Workers began using heavy excavation machinery to dig through the mud.

Most of the victims were Vale employees.

Five people who had been arrested for their role in validating the safety of the dam just months before it collapsed were released Tuesday pending further investigation.

Prosecutors in Brazil say three of those arrested were officials from the mining company Vale, whose responsibilities included dealing with environmental impact licenses. Vale said it was co-operating with prosecutors.

The company is the world’s biggest producer of iron ore and nickel.

On Monday, protesters gathered outside Vale’s corporate headquarters in Rio de Janeiro and daubed slogans including “Murderers!” on its walls.

In a statement following the arrests, Vale said: “With regards to the warrants served this morning, Vale informs that it is fully co-operating with the authorities. Vale will continue to support the investigations in order to determine the facts, in addition to the unconditional support to the families.”

Vale’s share price plunged by nearly 25% on Monday on the Brazilian stock market.