An Afghan official says authorities are deploying security forces to ensure that insurgents fighting to overthrow the government do not benefit from illegal mining.

Wednesday's statement comes after recent reports that the Taliban earn tens of millions of dollars each year from illegal extraction and export of minerals, which the government has failed to keep safe.

Sediq Sediqqi, Interior Ministry spokesman says Afghan forces will do more to secure mineral deposits and prevent illegal mining across the country. He says that mining has become a significant source of funding for the insurgents.

The Taliban war against the Kabul government is now in its 15th year.

London-based advocacy group Global Witness said recently that mineral smuggling is now the Taliban's second biggest source of funding, after drugs produced in the south.