Bogota, May 12 (IANS/EFE): At least 59 people were arrested in Colombia in what the defence ministry called "the hardest, most crushing blow" against illegal mining in the last 10 years.

"Operation Anostomus" was described at a press conference, on Monday, headed by Defence Minister Juan Carlos Pinzon and top commanders of military and police.

A total of 600 soldiers and police, supported by 22 aircraft and almost a dozen ships, carried out the mission that combed hundreds of square kilometres in the provinces of Guainia, Vichada, Vaupes, Guaviare and Caqueta.

As a result, 59 people including 12 members of the FARC guerrilla group were captured in the area.

The defence ministry said the crimes with which the detainees are charged include the invasion of protected areas, illegally bearing firearms and environmental contamination through the illicit exploitation of mine deposits.

Those under arrest were illegally extracting gold and strategic minerals like tungsten and coltan, considered to be of "national interest".

The authorities said the operation dismantled the illegal financial network of several units of FARC, which received 20 billion pesos ($8.4 million) a month for mining in the Cerro Tigre, Campo Alegre and Serrania de Naquen sectors.