A miner runs away from an illegal cassiterite mine during an operation conducted by agents of the Brazilian Institute for the Environment and Renewable Natural Resources, southeast of Para state, Brazil. (Ricardo Moraes/Reuters)

Environmental enforcement agents deep in the Amazon rainforest swooped down on an illegal mine in a dawn raid earlier this year, in a campaign to tamp down on activities that environmental groups say have reached epidemic scale.

The operation was carried out against a handful of what are now known to be hundreds of illegal Amazon mines in Brazil that have been catalogued for the first time in a study released on Monday.

(Ricardo Moraes/Reuters)

The project, co-ordinated by Brazilian advocacy group Instituto Socioambiental, maps all illegal mines in the Amazon rainforest that sprawls across Brazil, Venezuela, Colombia, Peru, Ecuador and Bolivia.

(Ricardo Moraes/Reuters)

As government helicopters descended along a river that had become stagnant pools ravaged by miners digging for gold, many of the miners fled deep into the rainforest.

(Ricardo Moraes/Reuters)

Shortly after, half a dozen were apprehended for questioning by camouflaged agents bearing machine-guns.

(Ricardo Moraes/Reuters)

The real target is not the muddy and often barefoot miners, who work in slave-like conditions for unknown local strongmen, according to agents of Brazil's environmental agency Ibama.

(Ricardo Moraes/Reuters)

Ibama said its primary target is the excavators and other heavy machinery that is expensive and harder to replace.

(Ricardo Moraes/Reuters)

Unable to haul away the machines, the agents set fire to them, sending black plumes of smoke hundreds of metres into the air.

(Ricardo Moraes/Reuters)

The raids last month targeted several illegal mines in two national parks in Brazil's Amazon. While the battle was won, this week's study indicates the war is far from over.

(Ricardo Moraes/Reuters)

Brazil is home to 453 illegal Amazon mines, according to a mapping project as part of a joint initiative between Instituto Socioambiental and other environmental groups.

The first-ever attempt to map all of the region's illegal mines has recorded 2,500 such operations across six Amazon countries, said co-ordinator Alicia Rolla.

(Ricardo Moraes/Reuters)

One aim of the project is to call attention to the "epidemic" scale of the illegal mining problem, which pollutes local communities' water with mercury and contributes to deforestation, Rolla said.

(Ricardo Moraes/Reuters)

She said she hopes environmental agencies will use it as a tool to help police the mines. Ibama needs more resources if it is to break up the hundreds of mines, she added.

"The studies show that illegal mining is increasing a lot," Rolla said. "I think the government needs to be more worried about giving Ibama more resources to do their job."