Protesters had set up barricades on the edges of the plaza Egyptian protesters streamed into Cairo's Tahrir Square on Sunday after a night of deadly clashes that signalled the start of a violent countdown to the first polls since Hosni Mubarak's ouster.
Prime Minister Essam Sharaf's cabinet was to hold crisis talks, state television said, as fresh clashes broke out on the outskirts of the square and anti-riot police fired off rounds of tear gas.
Dozens of protesters set up barricades on the edges of the plaza as marchers poured into the square, in scenes reminiscent of the 18 days of protests which toppled Mubarak in February.
Clashes overnight between protesters and police left two people dead and hundreds injured, sparking fears of a disruption of Egypt's first elections since the end of Mubarak's 30-year-rule, scheduled to kick off on November 28.
In makeshift hospitals set up in mosques around Tahrir Square, demonstrators received treatment for tear gas inhalation and for injuries from rubber bullets and birdshot.
The health ministry said 750 people were injured in the clashes in Tahrir Square, while demonstrations also spread to the cities of Alexandria, Aswan and Suez. About 40 policemen were among those injured, the interior ministry said.
A policeman in an armoured car fired rubber bullets into the Tahrir Square crowd, striking an AFP journalist in the forehead and shoulder, while a Western photographer was struck in the face.
The protesters chanted slogans against the Supreme Council of the Armed Forces which took power from Mubarak and demanded the ouster of Field Marshall Hussein Tantawi, his longtime defence minister who heads the SCAF.
Mohsen al-Fangari, a member of the council, insisted elections would go ahead as planned and that authorities were able to guarantee security.
"We will not give in to calls to delay the elections. The armed forces and the interior ministry are able to secure the polling stations," Fangari told a talk show on Egyptian satellite channel Al-Hayat.
A number of prominent political figures and intellectuals, including former UN nuclear watchdog chief Mohamed ElBaradei, earlier issued a call for a delay to the legislative polls.
They submitted a new transition roadmap which would see an elected constituent assembly draft a constitution and then a presidential election held to be followed by parliamentary polls.
The street protests saw the return of anti-riot police, the branch of the interior ministry most used by the Mubarak regime in its crackdown against protesters but rarely deployed since.
"Down with Tantawi," hundreds of demonstrators cried in Cairo's iconic Tahrir Square on Saturday, as they lobbed rocks and other objects at armed police.
Medics announced the deaths of Ahmed Mahmoud, 23, who sustained a bullet wound to the chest in Cairo, and Baha Eddin Mohamed Hussein, 25, hit by a rubber bullet in the Mediterranean city of Alexandria as protests spread from the capital.
In the Tahrir Square clashes, police fired tear gas and rubber bullets to break up a sit-in organised by some of the driving forces behind the Arab Spring revolt that ousted Mubarak on February 11.
Friday had seen tens of thousands pack into Tahrir for a rally to demand the army hand over power to civilian rule.
Police seized the square only to be beaten back by protesters who triumphantly retook it on Saturday evening chanting, "The people want to topple the field marshal," Tantawi.
One of the protesters, Ali Abdel Aziz, said security forces beat up people indiscriminately.
"They beat us harshly, they didn't care if it was men or women. The interior ministry must take responsibility. We have one demand, the military council must go," said the 32-year-old accountancy professor.
Protesters also fear a potential return to power by members of Mubarak's regime, who are blamed for much of the post-revolt violence.
"We didn't have a revolution so the people we removed could come back to parliament," said 30-year-old activist Ahmed Abol Enein. "None of the revolution's demands have been met."
The military says it will hand over power after a presidential election, which has yet to be scheduled. Parliamentary polls are to be held in phases starting later this month.