Casualties from two collapsed dams at a Brazilian iron ore mine owned by BHP Billiton and Vale mounted yesterday as rescue teams searched for dozens missing in the mud and debris left by the flood that devastated a village in the country’s southeast.

Firefighters confirmed 30 injuries and at least two deaths, but said the count was likely to rise as pouring rain slowed the search and mudslides knocked out roads and cell towers.

“I heard screaming and saw the water coming fast, about 15 or 20 metres high,” said survivor Antonio Santos, a construction worker who was at home in the village of Bento Rodrigues when the dams broke on Thursday afternoon.

Bento Rodrigues is 150 kilometres southeast of Belo Horizonte, Brazil’s third largest city and the capital of the mining state of Minas Gerais.

“Within 10 minutes the whole lower part of the village was destroyed, about 80 per cent of it,” he said in a gymnasium crowded with survivors in the nearby city of Mariana. Mr Santos said he knew of four people who were swept away, including two children and two adults in their 50s.

I heard screaming and saw the water coming fast, about 15 or 20 metres high

Firefighters said they did not know if they would find all of those swept away by the wall of water released by the successive bursting of the two dams holding iron ore tailings and waste from the nearby mine.

Television footage from the scene showed Bento Rodrigues, population 600, devastated by the fast-moving floods that tore off roofs, leveled trees and swept away cars. The floods extended as far as the town of Barra Longa, 80 kilometres away. The town was partially underwater.

Residents observing the Bento Rodrigues district covered with mud.

Hundreds of families were evacuated from the area after escaping to higher ground, Duarte Junior, the mayor of Mariana, 25 kilometres from the mine, told TV channel GloboNews after declaring a state of emergency yesterday. The head of emergency planning at Samarco, the joint venture company that runs the mine, told GloboNews of reports of seismic activity in the area in the hour leading up to the incident.

The University of Sao Paulo’s seismic centre reported four weak tremors near Mariana and the town of Ouro Preto. The centre said it recorded tremors magnitude 2 to 2.6 within an hour before the dams burst, but added it was impossible to say they caused the disaster without more extensive research.

The collapse paralysed operations at the mine, a joint venture between Vale and BHP Billiton, the world’s top iron ore miners, and raised fears of an expensive cleanup.