Eight Nobel peace prize winners, including Archbishop Desmond Tutu of South Africa, on Tuesday asked China to end its 'repressive' policies in Tibet and expressed their support to Tibetan spiritual leader Dalai Lama's efforts to achieve autonomy for his homeland. The support by Nobel laureates -- Jody Williams, Shirin Ebadi, Mairead Corrigan Maguire, Desmond Tutu, Rogoberta Menchu Tum, Adolfo Perez Equivel, Betty Williams and Wangari Maatai -- was contained in a signed letter