By Seán O'Regan 

At least seven people are confirmed dead, and another 200 are missing, after a dam collapsed at a mine in south-eastern Brazil.

The army is helping rescue efforts after the town of Brumadinho - in the south east of the country - was hit by a torrent of mud.

The country's President Jair Bolsanaro is expected to visit the area today, while State governor Romeu Zema said there was little chance of finding people alive.

It is not clear what caused the collapse of the dam, owned by Brazil's largest mining company Vale.

Rupture of tailings dam of the Vale mining company occurred today, 25th Jan, resulting in flooding that destroyed many villages, forests and river in Minas Gerais, Brazil.#environment #disaster #brazil pic.twitter.com/fBCAZyWk9V

— Bernardo Candido (@candidobm) January 25, 2019

The dam near Feijão iron ore mine burst at around three o'clock yesterday (Irish time), which flooded another dam further below.

Farms and neighbourhoods have been destroyed by waves of mud, leaving many locals trapped.

Yesterday's disaster comes after a larger dam collapsed in 2015, resulting in the deaths of 19 people, and the country's former environmental minister says that lessons have not been learned.

Marina Silva said in a Twitter post:

"Three years after the serious environmental crime in Mariana, with investigations still ongoing and no-one punished, history repeats itself as tragedy in Brumadinho."