A second wave of Vietnamese refugees arrived from 1978 to the mid-1980s. Political and economic instability under the new communist government led to a migration unprecedented in Vietnam. South Vietnamese, particularly former military officers and government employees, were sent to "re-education camps," which were really concentration camps, for intensive political indoctrination. Famine was widespread, and businesses were seized and nationalized. Chinese-Vietnamese relations soured when China became Vietnam's adversary in the brief Sino-Vietnamese War. To escape, many South Vietnamese fled on small, unsafe, crowded fishing boats. Over 70 percent of the first immigrants were from urban areas, but the "boat people" were generally lower socioeconomically, as most were peasant farmers or fishermen, small-town merchants or former military officials. Survivors were picked up by foreign ships and brought to asylum camps in Thailand, Malaysia, Singapore, Indonesia, Hong Kong, and the Philippines from which they entered countries that agreed to accept them.