Mexico has removed about 1,100 steel mills from the approved import register after discovering that many of them do not exist. The blast was designed to prevent Chinese and other foreign steel from entering the United States through Mexico under preferential North American trade rules. Mexican officials say imports from Vietnam are down 80 percent, while steel and aluminum imports from other countries, including China, are down about 30 percent.

Mexico has removed about 1,100 steel mills from the approved import register after discovering that many of them do not exist. The blast was designed to prevent Chinese and other foreign steel from entering the United States through Mexico under preferential North American trade rules. Mexican officials say imports from Vietnam are down 80 percent, while steel and aluminum imports from other countries, including China, are down about 30 percent.