Police fired tear gas and hundreds of protesters pelted them with rocks at a street between the U.S. Embassy and Tahrir Square, birthplace of the uprising that toppled president Hosni Mubarak's authoritarian regime nearly two years ago.
The protesters have been staging a sit-in at the square since Friday night to demand President Mohammed Morsi revoke his decrees.
By mid-day, hundreds were starting to gather in Tahrir, chanting against Morsi's decrees and the Brotherhood. A new banner in the square proclaimed, "The Brotherhood stole the country."
"We are here to bring down the constitutional declaration issued by Morsi," said one protester at Tahrir, Mahmoud Youssef.
Hundreds of lawyers meanwhile gathered outside their union building in downtown Cairo ahead of their march to Tahrir. "Leave, leave," they chanted, addressing Morsi.
The rally planned for later Tuesday, with marches from various parts of Cairo to converge on Tahrir, is to be a significant test of the opposition's ability to bring out supporters and the public against Morsi's edicts issued last week.
The opposition says the decrees give Morsi near dictatorial powers by neutralizing the judiciary at a time when he already holds executive and legislative powers. Key parts of the judicial system have denounced the measures.
Morsi, in office since June, says the decrees are necessary to protect the "revolution" and the nation's transition to democratic rule. His declaration made all his decisions immune to judicial review and banned the courts from dissolving the upper house of parliament and an assembly writing the new constitution, both of which are dominated by Islamists. The decree also gave Morsi sweeping authority to stop any "threats" to the revolution.
Morsi's supporters canceled a massive rally they had planned for Tuesday, citing the need to "defuse tension" after a series of clashes between the two camps since the decrees were issued Thursday.
But a spokesman for the Muslim Brotherhood, the fundamentalist group from which Morsi hails, said demonstrations supporting the president could go ahead outside the capital and that supporters would form human chains in some provinces to protect Brotherhood offices. Morsi's supporters say more than a dozen of their offices have been ransacked or set ablaze since Friday.
On Monday, Morsi met with the nation's top judges and tried to win their acceptance of his decrees. But the move was dismissed by many in the opposition and the judiciary as providing no real concessions.
[to top of second column]
Presidential spokeman Yasser Ali, said Morsi told the judges that he acted within his rights as the nation's sole source of legislation, assuring them that the decrees were temporary and did not in any way infringe on the judiciary. He underlined repeatedly that the president had no plans to change or amend his decrees.
According to a presidential statement late Monday, Morsi told the judges that his decree meant that any decisions he makes on "issues of sovereignty" are immune from judicial review.
The vaguely worded statement did not define those issues, but they were widely interpreted to cover declaration of war, imposition of martial law, breaking diplomatic relations with a foreign nation or dismissing a Cabinet. Morsi's original edict, however, explicitly gives immunity to all his decisions and there was no sign it had been changed.
The statement Monday did not touch the immunity that Morsi gave the constitutional assembly or the upper chamber of parliament, known as the Shura Council. It also did not affect the edict that the president can take any measures he sees as necessary to stop threats to the revolution, stability or public institutions. Many see that edict as granting Morsi unlimited emergency powers.
The Shura Council does not have lawmaking authorities but, in the absence of the more powerful lower chamber, the People's Assembly, it is the only popularly elected, national body where the Brotherhood and other Islamists have a majority. The People's Assembly was dissolved by a court ruling in June.
Rights lawyers and activists, however, dismissed Morsi's assurances as an attempt to defuse the crisis without offering concrete concessions.
One of the lawyers, Ahmed Ragheb, described the presidential statement and Ali's comments as "playing with words."
"This is not what Egyptians are objecting to and protesting about," he said. "If the president wanted to resolve the crisis, there should be an amendment to his constitutional declaration."
Press; By HAMZA HENDAWI and SARAH EL DEEB]
Copyright 2012 The Associated
Press. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.