BRUMADINHO, Jan 28 — Brazilian rescuers yesterday soldiered on in the search for hundreds of people missing after a breached mining dam triggered a deadly mudslide, but hopes of finding survivors dimmed more than two days after the disaster.

Search efforts were paralysed for much of the day on fears another dam could give way in the Vale SA iron ore mining complex in the state of Minas Gerais.

The collapsed dam at Vale's Corrego do Feijao mine buried mining facilities and nearby homes in the town of Brumadinho and killed at least three dozen people.

Firefighters spent yesterday morning evacuating thousands from their homes before resuming search-and-rescue efforts in the afternoon once civil defence authorities ruled out the risk of another dam burst and called off the evacuation.

"Until the last body is found, the fire department is acting on the possibility there could be people alive,” state fire department spokesman Pedro Aihara told reporters. "Obviously, given the nature of the accident, as time passes this chance will go down.”

Nearly 300 people were still missing, with the list of those unaccounted for being constantly updated, Godinho told reporters. Most of the missing are presumed dead, officials said.

The figure could rise as authorities reconcile its list of missing residents with the tally of Vale employees who are not accounted for, he said. The confirmed death toll rose to 37 by yesterday morning, according to the fire department.

The cause of the dam burst remained unclear. Recent inspections did not indicate any problems, according to the German firm that conducted the inspection.

Avimar de Melo Barcelos, the mayor of Brumadinho, blasted Vale for being "careless and incompetent,” and blamed the mining company for the tragedy and the state of Minas Gerais for poor oversight. He vowed to fine the miner 100 million reais (RM109 million).

Vale Chief Executive Officer Fabio Schvartsman said in a television interview yesterday the disaster had happened, even after the company followed experts' safety recommendations.

"I'm not a mining technician. I followed the technicians' advice and you see what happened. It didn't work,” Schvartsman said. "We are 100 per cent within all the standards, and that didn't do it.”

The CEO promised "to go above and beyond any national or international standards ... We will create a cushion of safety far superior to what we have today to guarantee this never happens again.”

Echoes of Samarco

In 2015, a tailings dam collapsed at an iron ore mine belonging to Samarco Mineracao SA, a Vale joint venture with BHP Group, less than 100 km to the east. The resulting torrent of toxic mud killed 19 people, buried a small village and contaminated a major river in Brazil's worst environmental disaster on record.

Fears of another dam burst in Brumadinho yesterday triggered evacuation sirens in the town before dawn, adding to the anxiety of residents still waiting for word about lost relatives and friends.

Fire department spokesman Aihara initially said 24,000 people would be evacuated, but later lowered the total to 3,000. In all, 24,000 people have been affected in some way by the disaster, he said.

Renato Maia, a 44-year-old salesman whose best friend's daughter remained missing, fled his home in panic early Sunday morning and waited for hours with his wife at a police barricade on the outskirts of town, stewing at the situation.

"We're all fed up with Vale ... and this is really adding to the tension,” he said. "It was a huge tragedy and now we don't know what might come next.”

The Brazilian government ordered Vale to halt operations at the Corrego do Feijao mining complex. Yesterday, courts nearly doubled to 11 billion reais the amount of Vale assets frozen in anticipation of damages and fines.

Federal prosecutor Jose Adercio Sampaio told Reuters on Saturday that state and federal authorities have failed to apply more stringent regulation to the hundreds of tailings dams around the country.

Schvartsman said all of Vale's tailings dams were checked after the 2015 disaster and periodic reviews are carried out. — Reuters