According to Mining News Pro - Vale said it had taken the decision for the protocol, which does not require the evacuation of nearby residents, in agreement with regulators after an anomaly was identified at the dam “during routine inspection.”

The move, which Vale said would not affect its 2019 production targets, is the latest in a series of emergency moves Vale has taken since the collapse of its tailings dam at Brumadinho, about 80 kilometers (50 miles) away, which killed more than 250 people in January.

As a result, the Forquila IV dam is expected to lose its stability certificate (DCE) from Brazil’s national mining regulator, Vale said, adding that the dam had not received new iron ore mining waste since February.

Three other nearby dams, Forquilha I, II and III, have already been halted because of what the regulator deems as a “Level 2” emergency.

Ouro Preto, known for its Portuguese colonial architecture, is a UNESCO world heritage site that is one of Brazil’s most visited towns.

A global inquiry into how mining companies store billions of tonnes of waste in huge dams, launched in the wake of the Brumadinha disaster, showed on Thursday that about a tenth of the structures have had stability issues.