Hosni Mubarak ceded power to the Egyptian military as a popular revolt swept away the leader of the Arab world's most populous state, throwing into question the future course of a reliable US ally in the Middle East.

Egyptians, who only hours earlier shouted anger that Mubarak was clinging to power, celebrated through the night in Cairo and other cities after an announcement that Mubarak had resigned, bowing to the demands of protesters who had occupied central Cairo for 18 days. In downtown's Mubarak subway station, revelers crossed out his name, replacing it with "Martyrs' Station."

After 30 years of autocratic rule by Mubarak, the only leader young Egyptians have known, the country begins a new day under a military council that promises to lead the country through a democratic transformation.

"The demonstrators are obviously overjoyed, but the way he resigned may ultimately make them wish they didn't get what they wished for," Nathan J. Brown, a professor of political science and international affairs at George Washington University, said in a telephone interview. "They don't have regime change. They have gotten rid of just one person."

Mubarak cedes power to military