sentences:  Tserendorj maintained his position as Minister of Foreign Affairs after the occupation of Niislel Khüree (present day Ulaanbaatar) by troops under the Chinese warlord Xu Shuzheng in late 1919.Xu installed a dictatorial regime, imprisoned leaders of Mongolia's independence movement such as Khatanbaatar Magsarjav and Manlaibaatar Damdinsüren, and placed the Bogd Khan under house arrest.In the face of Chinese threats to exile the Bogd Khan, Tserendorj, Prime Minister Gonchigjalzangiin Badamdorj and the Bogd Khan acquiesced and signed a document "voluntarily" abdicating Mongolia's autonomy to Chinese rule.