Longju or Longzu (Chinese: 朗久; pinyin: Lǎng jiǔ) is a disputed areain the eastern sector of the China–India border, controlled by China but claimed by India. The village of Longju is located in the Tsari Chu valley 2.5 kilometres (1.6 mi) south of the town of Migyitun, considered the historical border of Tibet. The area of Longju southwards is populated by the Tagin tribe of Arunachal Pradesh.