Walls of water filled with mining waste cascaded downhill, covering the village of Bento Rodrigues in a sea of red mud.

One person is known to have died while 30 others were injured, officials have said.

Towns 80km downstream were also hit by the deluge.

Residents of Bento, which has a population of 600 and lies 7km from the mine, said the only warning they got was a deafening clap of sound.

"Everything happened so quickly that I barely had time to save my kid goat, not even my property," one survivor named Claudio said.

Another survivor, Joaquim Dutra, said: "When I went outside there were already people running uphill, saying the dam burst. All I did was close my house and run to the top."

Dirce da Silva Mendes, a mother of two, said: "The mud has taken over the whole house. It also destroyed our orange trees, our fig trees. It is all gone. It was so quick."

Since Friday, hundreds of people have taken shelter in a gym in the nearby city of Mariana as donations of food, clothing and mattresses pour in.

Many have injuries to their feet after fleeing their homes barefoot.

Rescuers have been using small aeroplanes and a drone to track down the 19 people confirmed as missing - 13 of them mine workers and six Bento residents.

The mayor of Mariana has said he fears the death toll will inevitably rise.

"[It] will rise for sure... The number of missing will rise because we're talking to the residents of Bento and some people still aren't accounted for," Duarte Júnior told journalists.

The mine's operator, Samarco, issued a brief statement saying it "could not currently confirm the cause or size of the incident".

The company, which is jointly owned by the Australia's BHP Billiton and Vale of Brazil, also warned people to stay away from the area for the time being.

Samarco has not said when the mine, which produces around 30 tons of iron ore a year, is likely to re-open.