The Filipino strength at the beginning of the war was 20,000 soldiers but only 15,000 rifles. The number of rifles began the decline as the war raged on, as many malfunctioned, or captured by American troops. As ammunition ran low, Filipino troops manufactured their own gunpowder and cartridges. However this makeshift gunpowder would release black smoke which would reveal their position. Even with these flaws, Filipino infantry were tough and hardy, requiring few supplies, and demonstrated to overrun Spanish garrisons quite easily. However, they were still poorly trained and the officer corps was quite weak.