evidence: At least 20 Indian soldiers were killed in a bloody brawl with Chinese troops on Monday in the Galwan Valley, close to Aksai Chin, an area controlled by China but claimed by both countries. It is unclear if or how many Chinese soldiers died. Both sides have accused the other of overstepping the de facto border, the Line of Actual Control (LAC) that runs along the western sector of the valley. The details of the encounter remain confused, however, and may never be fully clear. [...] Aksai Chin,the area in contention, is claimed as part of Xinjiang by China and Ladakh by India. It is cold and inhospitable, draped in snow with temperatures around freezing, even in summer. Located high in the Himalayas, the average altitude is 14,000 feet (4,200 meters), almost double the height where altitude sickness kicks in, meaning any humans in the area have to undergo tedious, gradual acclimatisation or suffer crippling headaches, nausea and fatigue. [...] Aksai Chin is part of greater Kashmir, and after the bloody war between Pakistan and India in 1947 resulted in the partition of that region, the border between China and India was left ill-defined.