(Reuters) – U.N. human rights chief Michelle Bachelet can visit Xinjiang, China’s Foreign Minister Wang Yi said on Saturday, but China does not welcome any investigation based on the presumption of guilt. Bachelet has long sought access to the western Chinese region to investigate accusations of abuse against ethnic Uyghurs. The issue has strained ties between Beijing and the West, sparking accusations of genocide from Washington and a U.S.-led diplomatic boycott by some countries of the Winter Olympics in Beijing. “(China) rejects all kinds of biases, prejudices and uncalled-for accusations,”…