Embattled Egyptian President Hosni Mubarak is preparing to speak to the nation, which is undergoing unprecedented protests by tens of thousands of people.

Mubarak has also ordered the army into the streets to impose a curfew in Cairo, Alexandria and Suez.  

In addition, opposition leader and Nobel laureate Mohamed ElBaradei has been place under house arrest, the Associated Press reports, quoting security officials.

ElBaradei, the former head of the U.N. nuclear watchdog agency, returned to Cairo on Thursday evening, saying he would join protesters on the street. He attended Friday prayers today and was in the middle of skirmishes with riot police.

Another opposition figure, Ayman Nour, was hit by a rock during the demonstration and taken to the hospital, his son tells AlJazeera TV. His son says his father was "semi-conscious" when he was hospitalized. Nour, a former member of the Egyptian Parliament and chairman of the El Ghad party, was jailed in 2005 for his opposition activity.

President Hosni Mubarak is expected to address the crisis in coming days and institute major reforms. The official calls the situation "unprecedented" and says it calls for an untraditional response. He says it is "not a sign of weakness" to respond to the demands of demonstrators.  "This is a moment of wisdom and Egypt has to take action against corruption, against poverty, upgrading the standard of living of people, giving more freedoms," he says. "This should be considered now more than ever."