RIO DE JANEIRO, March 28 (Reuters) - Brazilian mining firm Vale SA activated alarms in areas below three tailings dams on Wednesday night due to an elevated risk of rupture, amid a tense atmosphere in Minas Gerais state where a dam burst in January killed about 300 people.
The company activated alarms in areas downstream of the B3/B4 dam and the Forquilha I and Forquilha III dams as a "preventative measure," after the structures failed to receive a safety certification from independent auditors.
There will be no new evacuations from the area, Vale said, as residents had vacated the relevant danger zones in February.
In late January, a tailings dam at Vale's Corrego do Feijao mine in Minas Gerais ruptured, unleashing a torrent of sludge that killed hundreds. It was the second deadly rupture of a Vale-linked dam in Minas Gerais in just over three years.
Since then, the firm has pledged to decommission dams built in a similar fashion to the ones that burst, and several executives, including the chief executive, have stepped down.
(Reporting by Gram Slattery; Editing by Bernadette Baum)