Kill Foreman Bonds and 10 Hillsbrad Miners and report back to Darthalia in Tarren Mill.
The Hillsbrad Town Registry indicates that the Azureload Mine is under Alliance control. Furthermore, the mine is a prime source of iron ore for the Alliance armories.
Even though we've struck a decisive blow to the town of Hillsbrad, the Alliance still supports and protects the Azureload Mine fervently.
The mine lies due south of Hillsbrad. Go there and slay the foreman, a human by the name of Bonds. Kill his miners as well. That should send a clear message to the Alliance.