More than 200,000 Egyptian protesters flocked to the capital's Tahrir Square for a massive evening rally organized by opponents of Islamist President Mohammed Morsi, demanding that he rescind decrees granting him near-absolute powers.

The massive, flag-waving, chanting crowd in Cairo's iconic plaza rivalled the size of some of the large protests of last year's uprising that drove autocrat Hosni Mubarak from office. The same chants used against Mubarak were used again against Egypt's first freely elected leader.

"The people want to bring down the regime," and "erhal, erhal" — Arabic for "leave, leave," rang across the square.

Protests in Tahrir Square and several other cities Tuesday were sparked by edicts issued by Morsi last week that effectively neutralized the judiciary, the last branch of government he does not control.

But it turned into a broader outpouring of anger against Morsi and the Muslim Brotherhood, which opponents say have used election victories to monopolize power, squeeze out rivals, and dictate a new, Islamist constitution, while doing little to solve Egypt's mounting economic and security woes.

Clashes between protesters and police broke out earlier Tuesday near the U.S. Embassy and in Tahrir Square — the birthplace of the uprising that toppled Mubarak's regime nearly two years ago.

Skirmishes erupted on the outskirts of the square as police tried to contain protesters and keep them from spilling into surrounding streets, CBC's Susan Ormiston reported. Police also fired tear gas after hundreds of protesters pelted them with rocks in a street leading from the square to the embassy.

The parliament building and the prime minister's office were barricaded with riot police standing guard behind the barriers.

Tensions in the square appeared to cool as the day wore on, with people painting faces and selling food, hats and flags, Ormiston said.

Morsi’s party, the Muslim Brotherhood, had cancelled its own planned rally over fears of violence between the rival groups.

But a spokesperson for the group said that demonstrations supporting the president could still go ahead outside the capital and that supporters would form human chains in some provinces to protect Brotherhood offices.

Gehad el-Haddad, a senior adviser to the Brotherhood and its political party, said Morsi would not back down on his edicts.

"We are not rescinding the declaration," he said.

That sets the stage for a drawn-out battle between the two sides that could throw the nation into greater turmoil.

Protest organizers on a stage in the square called for another mass rally on Friday. If the Brotherhood responds with mass rallies of its own, as some of its leaders have hinted, it would raise the prospect of greater violence after a series of clashes between the two camps in recent days.

A Tweet by the Brotherhood warned that if the opposition was able to bring out 200,000 to 300,000 "they should brace for millions in support" for Morsi.

Demands to revoke decrees

The protesters have been staging a sit-in at the square since late last week, demanding that President Mohammed Morsi revoke his autocratic decrees.

Morsi met with Egypt's top judges on Monday to reassure them that the decrees did not in any way "infringe" on the judiciary.

The meeting did little to convince the protesters in Tahrir Square, said CBC's Margaret Evans.

"They say they feel [Morsi’s] shown his true face. They believe he has an agenda they don’t agree with," Evans said. "They believe that they fought, lost loved ones for the revolution and that he’s now basically betraying the ideals of that revolution."

Morsi, in power since June, says the decrees are necessary to protect the "revolution" and the nation's transition to democratic rule.