Nelspruit — Mpumalanga's sand miners who dig mineral rich soil to sell to pregnant women craving nutrients have been warned to stop.

The Mbombela municipal council said sand mining in tribal areas around Nelspruit, White River and Hazyview was having a detrimental affect on the environment.

"[This is] a serious problem because the areas erode easily and huge dongas and other environmental damage is created," said council spokeswoman Delia Oosthuizen.

The mining was sometimes so extensive that gravel roads were under threat of being washed away, she said.

In one case in Daantjie near Nelspruit, the council was forced to use R30 000 from its gravel road maintenance fund to rehabilitate damaged land near a primary school.

"There is also the danger that children could fall into the pits and hurt themselves," she said.

A public awareness campaign is being launched and police will be enlisted to enforce the conditions set out by the minerals and energy affairs department.

Oosthuizen said the council would also formulate policies and by-laws to control sand mining.

"Suitable areas for sand mining will be identified, and the already damaged sites will be fenced off and warning signs put in place," she said.

Rural residents dig the soil to sell to pregnant women as well as for use in pottery and to build mud houses.