In March 2011, police snipers opened fire on a pro-democracy camp in Sana'a, killing more than 50 people. In May, dozens were killed in clashes between troops and tribal fighters in Sana'a. By this point, Saleh began to lose international support. In October 2011, Yemeni human rights activist Tawakul Karman won the Nobel Peace Prize, and the UN Security Council condemned the violence and called for a transfer of power. On 23 November 2011, Saleh flew to Riyadh, in neighbouring Saudi Arabia, to sign the Gulf Co-operation Council plan for political transition, which he had previously spurned. Upon signing the document, he agreed to legally transfer the office and powers of the presidency to his deputy, Vice President Abdrabbuh Mansur Hadi.