Image copyright Getty Images Image caption Millions of tonnes of waste were released in the dam's collapse

Brazilian prosecutors have filed homicide charges against 21 people a year after an iron ore mine disaster in the state of Minas Gerais.

They include several Brazilians, two Americans, a South African, an Australian, a Briton and a French man.

The accused were employed at the time by the companies involved - Brazil's Samarco and Vale, and BHP Billiton.

In November 2015 a mine dam burst, killing 19 people and polluting miles of Brazil's waterways.

According to the lead prosecutor in the case, Jose Leite Sampaio, the companies were aware there was a risk of collapse but ignored it. They immediately rejected the charges and said they would defend their staff.

Mr Sampaio accused Brazilian mining company Vale, Anglo-Australian giant BHP Billiton and iron ore producer Samarco, which they co-own, of pursuing profits rather than attending to safety.

"Security was always of secondary importance. The increase in production at Samarco sought to compensate for the falling value of the ore in order, not only to maintain, but also to boost profits and dividends," Mr Sampaio said in a televised news conference near the site of the disaster.

Support for accused

Vale said in a statement that it "vehemently rejects the charges" and that it would defend its staff members. It said the evidence showed there was no knowledge the dam could fail before the collapse.

BHP said it "rejects outright the charges against the company and the affected individuals. We will defend the charges against the company, and fully support each of the affected individuals in their defence."

Before the case can go to trial, the charges need to be approved by a judge.

Image copyright AFP Image caption Horses, mules and dogs got stuck in the mud, which travelled miles downstream

Millions of tonnes of muddy mine waste were released on 5 November 2015 when a dam collapsed. A village was flattened and drinking water was affected for hundreds of thousands of people. The sludge eventually pooled out into the Atlantic Ocean.

The disaster drew comparisons with the Deepwater Horizon oil rig disaster in the Gulf of Mexico, as the Brazilian authorities sought redress for the environmental devastation from the companies it deemed responsible.

Analysis: Daniel Gallas, South America Business Correspondent, Rio de Janeiro

The mining companies have managed to reach a deal with Brazil's environmental authorities to set up an institute that will help clean up the pollution and rebuild some communities for the next 10 years.

But prosecutors tasked with finding the guilty parties are less willing to compromise.

In a 273-page document, they blamed top managers, accusing them of merely using "bandages" to deal with a serious threat.

Prosecutors also want the accused to respond to a popular jury, assuming these charges get the go-ahead from the judge.

The companies responded by accusing prosecutors of ignoring the evidence against those claims.

As the Samarco tragedy approaches its first anniversary, it seems that this case will still drag on for years to come.

The accused include Ricardo Vescovi, who was chief executive of Samarco at the time of the disaster.

Under Brazilian law qualified homicide is similar to, but more serious than, a manslaughter charge. The accused, if found guilty, could face sentences of up to 54 years.