SAN DIEGO — The California-Mexico border region was rocked by a magnitude-5.7 quake, rattling nerves from San Diego north to Orange County and Los Angeles.The US Geological Survey said the quake was centered five miles (eight kilometers) southeast of Ocotillo in Imperial County — about 85 miles (137 kilometers) east of San Diego. It struck Monday at about 9:26 p.m. PDT (0426 GMT) and has been followed by dozens of aftershocks.