In the central and southern mountains, Mon-Khmer-speaking groups, known as Lao Theung or mid-slope Laotians, predominate. Other terms are Khmu, Khamu (Kammu) or Kha as the Lao Loum refer to them to indicate their Austroasiatic language affiliation. However, the latter is considered pejorative, meaning 'slave'. They were the indigenous inhabitants of northern Laos. Some Vietnamese, Laotian Chinese and Thai minorities remain, particularly in the towns, but many left after independence in the late 1940s, many of whom relocated either to Vietnam, Hong Kong, or to France. Lao Theung constitute about 30% of the population.