Seven workers injured in a rock burst at a Hecla Mining Co. silver mine in Idaho were treated at local hospitals, and operations have been halted, the company said Thursday.

All miners were removed from the Lucky Friday mine near Mullan, Idaho, following a rock burst that occurred Wednesday evening.

The incident occurred at 5,900 feet below the surface. Seven people were transported to local hospitals and treated for non-life-threatening injuries.

No mine blasting had taken place anywhere in the mine for the previous 24 hours, therefore the rock burst is unrelated to mining activities, Hecla said in a statement.

The mine is currently closed pending further investigation. The federal Mine Safety and Health Administration has been notified and investigators were en route to the mine.

Shares of Hecla rose in premarket trading seven cents to $5.80.