Authorities in Ha Giang Province bordering China have banned three companies from carrying raw ores across the border.
The companies include Nhat Anh, which was caught smuggling lead ores, Duc Son smuggling iron ores, and Ban Mai smuggling manganese ores.
Local authorities said illegal smuggling of raw minerals from the northern mountainous province has increased recently.
Residents in the province said they have seen tens of trucks every week carrying ores from mines along the border to sell across Xin Cai and Pho Bang border gates.
Some trucks even transport ores from mines located further inside the province. They are protected by officials and manage to reach the border, the residents said.
Further investigations into the smuggling are going on.