Madagascar's opposition leader declared himself president on Saturday and appointed a prime minister as head of a transition government in a new challenge to embattled leader Marc Ravalamona. Opposition supporters with a military escort entered the existing prime minister's office without meeting any resistance and proclaimed Monja Roindefo Zafitsimivalo as the new premier. The proclamation declared that the "high authority of transition" presided over by opposition leader Andry Rajoelina would "assume the functions of the president of the republic." Rajoelina, who has been in hiding for fear of arrest for two weeks, appeared before 10,000 supporters in a demonstration at a downtown square. There were no immediate reports of any violence.