In the caves, scientists discovered human bones as well as infant corpses sealed in niches in the walls and covered by rocks.
Local Tashkurgans buried stillborn babies this way a few decades ago, according to Ai Tao from the Xinjiang Archeological Institute.
In 2013, a cluster of 102 tombs were discovered in nearby Kezilesu Kirgiz Autonomous Prefecture.
Scientists think ritualistic cave burial was practiced as far back as 4,000 years ago.
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