evidence: China and India share a disputed 3,440km (2,100 mile) long de facto border - called the Line of Actual Control, or LAC - which is poorly demarcated. The presence of rivers, lakes and snowcaps means the line can shift. China continues to stake claim on the whole of Arunachal Pradesh, calling it "South Tibet". [...] The latest tensions began after the Chinese Ministry of Civil Affairs on 1 April announced that it had "standardised some geographical names in southern Tibet".