The national union of mining and metal workers are staging 2 strikes, each against a different company and in a different place in Mexico. One in Cananea (Sonora, in northwestern Mexico, a few miles from Nogales, AZ) and Taxco (Guerrero, southwestern Mexico, in between Acapulco and Mexico City).
The good news is that a federal judge granted legal validity to the strikes by ruling in favor of the union and against resources of injunction interposed by the companies in both cases. The miners in Sombrerete (Zacatecas, central Mexico) may go on strike as well for their own reasons.
In all cases, the main demand for the strikes is improvement in working conditions -- basically safety and hygiene.