Industrial production in the state centers on metal products, machinery and equipment, accounting for about 24% of the total. Non-metallic minerals, other than petroleum account for about 25%. However, the most important industry is automobile and train engine production, which is followed by the refining of petroleum products, based mostly in Tula. Automotive and train production is centered in Ciudad Sahagún. Most of the automobiles produced are sold in Mexico City. Other industries include the production of cement in Tula de Allende and textiles in Tepeji del Río and Tulancingo. This employs about 30% of the population.