After South Vietnam's fall in April 1975, the new government sent up to 300,000 former officials, military officers, and others associated with the old regime to re-education camps, while forcibly relocating roughly one million urban residents to rural "New Economic Zones." Facing political repression, economic hardship, and (from 1978) an exodus of ethnic Chinese, an estimated 1.6 million or more Vietnamese fled the country between 1975 and the mid-1990s, most notably around 800,000 "boat people" who crossed the South China Sea in often unseaworthy vessels toward Hong Kong, Malaysia, Thailand, and Indonesia. Tens to hundreds of thousands are believed to have died at sea from storms, starvation, or piracy, though precise figures are disputed. The crisis prompted large-scale international resettlement and, eventually, the 1989 Comprehensive Plan of Action, under which many later arrivals were screened and repatriated.
The new communist government of unified Vietnam sent former South Vietnamese officials and soldiers to re-education camps and forced many urban residents to New Economic Zones, while hundreds of thousands fled by boat to neighboring countries
The Republic of Vietnam's population at the fall of Saigon is generally put at 19-20 million, based on late South Vietnamese administrative estimates and the 1979 census of unified Vietnam, which counted 52.7 million nationally.
The Migration Policy Institute reports that 'UNHCR estimates that as many as 400,000 people died at sea from weather, piracy, starvation, or illness' during the Indochinese exodus, in which more than 2 million people including 1.6 million Vietnamese fled. Because no register of departures exists, the figure is an upper-bound inference from survivor testimony and vessel losses, and other researchers argue the true toll is in the tens of thousands. Deaths in the re-education camps are separately estimated in the tens to low hundreds of thousands by émigré scholars, but those estimates are contested and Vietnam has never published figures.
UNHCR and the Migration Policy Institute document deaths at sea from piracy, starvation and illness — including systematic rape of women by pirates in the Gulf of Thailand — while Amnesty International's 1981 mission report to Vietnam documented detention without charge or trial and compulsory labour in the re-education camps.
Cambodia, Hong Kong, Singapore