Egypt's Mubarak Steps Down, Hands Power to Military
But injecting a note of caution about the military's role in Egypt's future, Katatni said the Brotherhood awaits the next steps to be taken by the Higher Military Council which has taken charge of the country's affairs after Mubarak's decision.
"This is the greatest day of my life," said opposition activist and Nobel Peace laureate Mohamed ElBaradei, welcoming a period of sharing of power between the army and the people.
He told Reuters that running for president was not on his mind.
"This nation has been born again, these people have been born again, and this is a new Egypt," said Ayman Nour, the only politician who dared to challenge Mubarak in Egypt's only multi-candidate presidential election. He came a distant second.
They waved flags, set off fireworks and beat drums to celebrate this new chapter in modern Egyptian history.
SMS text messages of congratulation zapped over mobile phone networks among ordinary Egyptians, hailing a victory for people power.
A speaker made the announcement in Tahrir Square where hundreds of thousands danced and sang, chanting: "The people have brought down the regime." Others shouted: "Allahu Akbar (God is greatest)." Women ululated in jubilation.
"I think you could see some contagion in terms of protests; Morocco, perhaps Jordan, Yemen," said Anthony Skinner of political risk consultancy Maplecroft.
Israel, with whom Egypt signed the first Arab peace treaty in 1979, said it hoped relations would remain peaceful.
The confrontation had raised fear of uncontrolled violence in Egypt, a linchpin U.S. ally in an oil-rich region where the chance of chaotic unrest spreading to other long stable but repressive states troubles the West.
Swiss authorities said they had frozen assets that may belong to Mubarak.
Washington has called for a prompt democratic transition to restore stability in Egypt, a rare Arab state no longer hostile to Israel, guardian of the Suez Canal linking Europe and Asia and a major force against militant Islam in the region.