Authorities in the Central Highland Province of Lam Dong destroyed an illegal underground tin mine on Wednesday.
The mine had been dug in the Da Nhim protected forest in Lac Duong District. Authorities discovered that the subterranean operation consisted of around 90 interconnected tunnels of varying sizes. The system has spread to a nearly 10-hectare area.
It took an official demolition team more than four hours to collapse the tunnel system and pull down all surrounding tents.
The miners had wired the tunnels with electricity and set up makeshift homes in the remote area, so it was hard to notice them.
According to local officials, illegal tin excavation has persisted in remote and rugged parts of the region for many years but the authorities have not divined an effective means to combat it.
Several months ago, the authorities used dynamites to collapse the tunnels but new ones cropped up soon afterwards.
Most of the excavators came from outside the province and it's hard to keep track of them, the officials said.
"The situation is complicated," said Pham Trieu, vice chairman of Lac Duong District. "The excavators are all operating here under several dealers and most of them are offenders from other localities."
"We're determined this time"¦ The excavators will be expelled and investigations will be launched into the dealers."
Trieu said the area will be temporarily controlled by the police before being returned to the forest planters.
In related news, the amended Mineral Law was approved at the National Assembly session 17, which requires individuals or organizations to secure permission for mineral excavation through "public and transparent" bidding.
The bidding will raise money for the state budget and prevent corruption, deputies said at the meeting.
If the minerals are deemed economically strategic or they are located in areas with high environmental or national security importance, the bidding process will be eschewed and permission will have to be obtained directly from the the Prime Minister.
The new law, which will take effect next July, will allow individuals and organizations up to five permits apiece for conducting mineral surveys.