The Yi or Nuosuo people, are an ethnic group in China, Vietnam and Thailand. Numbering nine million people, they are the seventh largest of the 55 ethnic minority groups officially recognized by the People's Republic of China. They live primarily in rural areas of Sichuan, Yunnan, Guizhou and Guangxi, usually in mountainous regions. Liangshan Yi Autonomous Prefecture is home to the largest population of Yi people within mainland China, with two million Yi people in the region. For other countries, as of 1999, there were 3,300 Mantsi-speaking "Lô Lô" people living in the Hà Giang, Cao Bằng and Lào Cai provinces in Northern Vietnam.