Last Updated 7:30 p.m. ET
CAIRO - Egyptian riot police firing tear gas and rubber bullets stormed into Cairo's Tahrir Square Saturday to dismantle a protest tent camp, setting off clashes that killed one protester, injured hundreds and raised tensions days before the first elections since Hosni Mubarak's ouster.
The scenes of protesters fighting with black-clad police forces were reminiscent of the 18-day uprising that forced an end to Mubarak's rule in February. Hundreds of protesters fought back, hurling stones and setting an armored police vehicle ablaze.
The violence raised fears of new unrest surrounding the parliamentary elections that are due to begin on Nov. 28. Public anger has risen over the slow pace of reforms and apparent attempts by Egypt's ruling generals to retain power over a future civilian government.
Witnesses said the clashes began when riot police dismantled a small tent camp set up to commemorate the hundreds of protesters killed in the uprising and attacked around 200 peaceful demonstrators who had camped in the square overnight in an attempt to restart a long-term sit-in there.
"Violence breeds violence," said Sahar Abdel-Mohsen, an engineer who joined in the protest after a call went out on Twitter urging people to come to Tahrir to defend against the police attacks. "We are tired of this and we are not leaving the square."
Police fired rubber bullets, tear gas and beat protesters with batons, clearing the square at one point and pushing the fighting into surrounding side streets of downtown Cairo.
A 23-year-old protester died from a gunshot, said Health Ministry official Mohammed el-Sherbeni. At least 676 people were injured, he said.
Crowds swarmed an armored police truck, rocking it back and forth and setting it ablaze.
After nightfall, protesters swarmed back into the square in the thousands, setting tires ablaze in the street and filling the area with an acrid, black smoke screen. Police appeared to retreat to surrounding areas, leaving protesters free to retake and barricade themselves inside the square. The air was still thick with stinging tear gas.
Shortly before midnight, police pushed back toward the square, firing more tear gas and drawing a barrage of stones from the protesters holding the site.
The government urged protesters to clear the square.
A member of the military council, Gen. Mohsen el-Fangari, dismissed the protesters and said their calls for change ahead of the election were a threat to the state.
"What is the point of being in Tahrir?" he said, speaking by phone to the popular Al-Hayat TV channel. "What is the point of this strike, of the million marches? Aren't there legal channels to pursue demands in a way that won't impact Egypt ... internationally?"
"The aim of what is going on is to shake the backbone of the state, which is the armed forces."
In a warning, he said, "If security is not applied, we will implement the rule of law. Anyone who does wrong will pay for it."
Saturday's confrontation was one of the few since the uprising to involve police forces, which have largely stayed in the background while the military takes charge of security. There was no military presence in and around the square on Saturday.
The black-clad police were a hated symbol of Mubarak's regime.
"The people want to topple the regime," shouted enraged crowds, reviving the chant from the early days of the uprising. Crowds also screamed: "Riot police are thugs and thieves" and "Down with the Marshal," referring to Field Marshal Hussein Tantawi, Egypt's military ruler.
Some of the wounded had blood streaming down their faces and many had to be carried out of the square by fellow protesters to waiting ambulances.
Human rights activists accused police of using excessive force.
One prominent activist, Malek Mostafa, lost his right eye from a rubber bullet, said Ghada Shahbender, a member of the Egyptian Organization for Human Rights.
At least four protesters were injured in the eyes as a result of what Shahbender said were orders to target protesters' heads.
"It is a crime," she said. "They were shooting rubber bullets directly at the heads. ... I heard an officer ordering his soldiers to aim for the head."
A videojournalist for the Egyptian newspaper Al-Masry al-Youm, Ahmed Abdel-Fatah, was also hit in the eye by a rubber bullet and was undergoing surgery.
Police arrested 18 people, state TV reported, describing the protesters as rioters.
Protests were also held Saturday in the Red Sea port city of Suez, where a crowd of thousands attacked a police station, with some hurling firebombs at the building, said protester Ahmed Khafagi. They were met with tear gas and gunfire.
In Alexandria, hundreds of people threw stones at the main security headquarters, said protester Ahmed Abdel-Qader. He said it felt like the revolution was starting all over again.
"We only managed to bring down the head of the regime. The rest of the tree is still standing," he said.
A day earlier, tens of thousands of Islamists and young activists had massed in Tahrir Square to protest Egypt's ruling military council, which took control of the country after Mubarak's ouster and has been harshly criticized for its oversight of the bumpy transition period.
Friday's crowd, the largest in months, was mobilized by the Muslim Brotherhood and focused its anger on a document drafted by the military that spells out guiding principles for a new constitution.
Under those guidelines, the military and its budget would be shielded from civilian oversight. An early version of it also said the military would appoint 80 members of the 100-person constitutional committee -- a move that would vastly diminish the new parliament's role.
Groups across the political spectrum rejected the document, calling it an attempt by the military to perpetuate its rule past the post-Mubarak transition. Back in February, the military had promised it would return to the country to civilian rule within six months. Now, there is deep uncertainty over the timeline, and presidential elections might not be held until 2013.
El-Fangary said if the plan in place is followed, the military will be out of power by the end of 2012.
Friday's demonstration dispersed peacefully, but several hundred people remained in the square overnight in an attempt to re-establish a semi-permanent presence in the square to pressure the military council.
Violence began Saturday morning, as police moved in to clear them.
The Interior Ministry, which runs the country's police forces, accused people of trying to escalate tensions ahead of the parliamentary elections, which will be held in stages that continue through March.
Activists say they just want to guard the outcome of their revolution.
Unemployed graduate student Nasser Ezzat said he traveled from southern Egypt to Tahrir because he wanted to help finish the revolution that people died for. He came to the square on Friday, leaving behind his a pregnant wife in the city of Sohag.
"I dream of a fairer Egypt for my unborn daughter, one without police harassment and corruption," he said on Saturday.