In a surreal scene resembling the movie "Ben Hur," supporters of embattled Egyptian President Hosni Mubarak thundered through the crowds on horses and camels in central Tahrir Square. At least one man was pulled off his horse and beaten.
Mubarak's announcement that he will not seek re-election had been expected to vacuum passion out of Egypt's nine-day uprising.
But the opposite rang true, at least in central Cairo, where mob rule was in sharp contrast to the jubilant mood of tens of thousands of anti-Mubarak protesters the day before.
It remained unclear whether such confrontations were being repeated elsewhere.
The sound of gunfire reverberated in Tahrir Square and people hurled verbal insults, Molotov cocktails, rocks and anything else they could find -- shards of metal, sticks, shoes -- at one another. Desperate for more ammunition, they dismantled sidewalks and picked up chunks of cement to throw. They beat each other in what rapidly spiraled into utter mayhem.
Through the course of the afternoon, pro-Mubarak forces added to their ranks and eventually overturned a military vehicle to surge forward past the Egyptian National Museum toward the center of Tahrir Square. Flames leapt from the awnings and doorways of several burning buildings and thick black smoke filled the air.
Some people expressed fears to journalists that a bloodbath would ensue.
Scores of people have already been wounded. Blood streaming down their faces, they were carried away from the square into a nearby makeshift clinic.
Protesters climbed atop army tanks, waving flags and chanting loudly.
Each side in the chilling street battle fought to lay claim to this patch of central Cairo territory that has all along been the symbol of the uprising. But despite the extremely volatile altercations, the police were nowhere to be seen and the army did little.
Mubarak deployed the army last Friday after police forces -- who don't have a clean track record with the Egyptian people -- used excessive force on protesters.The army said it would not attack peaceful demonstrations but Wednesday morning, it urged a return to normalcy.
"Your message is received ... (your) demands became known," a Defense Ministry spokesman said on state-run television. "And we are here and awake to protect the country for you ... not by power but by the love to Egypt. It is time to go back to normal life."
But the situation in Tahrir Square brought to question how long soldiers would stand by passively.
Egyptian Finance Minister Samir Radwan said the army has made its mission clear: it will not harm its own people. He said the government was urging opposition leaders to begin dialog.
"I don't care who's responsible," Radwan said of the ongoing chaos. "But I think any wise person should come to the table. This is not a blaming game. I am trying to save my country."
Egypt's state-run Nile TV sought to portray the unrest as a "foreign conspiracy" fueled by international journalists. Despite reports that shots had been fired, the television network's reporters denied any shooting had taken place and even that violence had broken out in Tahrir Square.
The dramatic and potentially deadly situation Wednesday erupted after pro-Mubarak demonstrators broke through a barricade separating them from anti-government protesters who have been amassing more than a week in the downtown plaza.
Contesting rallies were also taking place further north in Alexandria, where clashes Tuesday night injured a dozen people. Wednesday afternoon, the demonstrations in the coastal city were still peaceful but extremely tense.
In Washington, the Obama administration renewed its call for calm Wednesday.
"We continue to watch the events very closely, and it underscores that the transition needs to begin now," said White House Press Secretary Robert Gibbs, adding that there needs to be "real change" in Egypt.
United Nations Secretary General Ban Ki-moon echoed those sentiments after a meeting in London with British Prime Minister David Cameron.
"I once again urge restraint to all the sides," Ban said. "Any attack against peaceful demonstrators is unacceptable and I strongly condemn it."
Angry Egyptians, fed up with Mubarak's rule, have camped out in the Egyptian capital's central plaza for a week. The burgeoning demonstrations led to the "march of millions" on Tuesday.
Earlier Wednesday, the crowds were smaller and the mood altered after Mubarak announced his intention not to seek re-election. Voices defending the government became increasingly louder. They called the media "traitors" and "agents" and said the country cannot survive without Mubarak.
It was unclear how many were out on the streets on their own volition. Three employees of the national petroleum company told CNN they were forced to demonstrate Wednesday.
There were reports that among the pro-Mubarak camp were police in civilian clothing but an Interior Ministry spokesman denied on state-run television that police identification cards had been confiscated. He said if they had, they were stolen or fake.
In his televised address Tuesday night, Mubarak announced he will not seek office again in elections scheduled for September, but vowed to stay in the country and finish his term.
"My first responsibility now is to restore the stability and security of the homeland, to achieve a peaceful transition of power in an environment that will protect Egypt and Egyptians, and which will allow for the responsibility to be given to whoever the people elect in the forthcoming elections," Mubarak said.
But the concession, large and remarkable for a man who has held a tight grip on power for three decades, may have been too little and too late for many Egyptians.
"He is unfortunately going to continue the agony for another six or seven months," said opposition leader Mohamed ElBaradei.
"He's going to continue to polarize the country," said the Nobel Peace Prize winner. "He's continuing to get people even more angry and could result to violence. Whoever gives him that advice gave him absolutely the wrong advice. He just has to let go."
Mubarak's announcement largely rang flat in Tahrir Square, where thousands of protesters erupted in chants of "Down with Mubarak!" and "The people want the president to be judged!" following his announcement Tuesday. Some waved shoes in the air -- a deep insult in the Arab world -- and said they would continue their demonstrations until Mubarak quits outright.
But Arab League Secretary-General Amre Moussa, a former Egyptian foreign minister, said demonstrators should weigh what Mubarak has said before responding.
"I'm aware that there are certain currents in Egypt that will not see that as satisfactory and they need more," Moussa, a possible presidential contender himself, told CNN. But, he added, "I believe that there is something new that has been offered."
Walid Tawfeeq, a Mubarak supporter, said not all Egyptians agree that Mubarak should step down immediately.
"Not everybody wants President Hosni Mubarak out," Tawfeeq said. "There are elements in the government that needed to be changed. ... There is reform. There is economic reform, but ... change will not happen overnight. There's not a magical button for change. Change will take time."
Mubarak has led Egypt for nearly 30 years since the 1981 assassination of his predecessor, Anwar Sadat, aided by an emergency decree that has allowed him to rule with an iron fist. But following demonstrations that have only grown in the past week, the 82-year-old former air force general told his people Tuesday night, "I have spent enough time serving Egypt."
"I will pursue the transfer of power in a way that will fulfill the people's demands, and that this new government will fulfill the people's demands and their hopes for political, economic and social progress," he said.
The Egyptian parliament has been suspended until a full judicial review is conducted of the November-December 2010 parliamentary elections.
The government also shortened its curfew by a few hours compared to recent days, though many protesters have ignored the orders to stay inside. The new curfew lasts from 5 p.m. Wednesday until 7 a.m. Thursday.
Banks and schools have been closed during the demonstrations, teller machine screens were dark and gas stations have run out of fuel. Long lines snaked around bakeries and supermarkets as shops began to ration how much food customers could buy.
Mubarak's announcement came less than three weeks after a wave of protests forced Tunisia's longtime strongman to flee to Saudi Arabia in mid-January.
As in nearby Tunisia, the Egyptian protests have been fueled by economic woes, including a dramatic rise in the cost of living coupled with high unemployment. Despite the government's food subsidies, people are struggling, with an estimated 40 percent of the country living in poverty.
The majority of Egypt's population -- and the vast majority of its unemployed -- is under 30, and many protesters are young men looking for economic opportunities and a better life.
As the demonstrations grew, Mubarak fired his Cabinet and ordered newly appointed Vice President Omar Suleiman to hold talks on political reform with opposition leaders.
The demonstrations turned ugly last Friday, when thousands of riot and plainclothes police used brutal force to crack down on people on the streets. Since the weekend, the army has replaced police as the enforcers of security, and the gatherings, until Wednesday, had been largely peaceful.
In recent days, protests inspired by the Tunisian outcome have spread to Algeria, Yemen, Jordan and Sudan. Calls for political reform prompted Jordan's King Abdullah II Tuesday to dismiss his government and appoint a new prime minister. A Facebook page urged similar demonstrations in Syria.
And in Yemen, President Ali Abdullah Saleh -- who has been in office for 32 years -- said Wednesday he will not run for president nor hand over power to his son once his current term ends in 2013. Still, many Yemenis said they will proceed with their planned a "day of rage" protests Thursday.
John Entelis, director of Middle East studies at New York's Fordham University, said the Arab world is facing a "wave" of unrest sparked by the Tunisian revolt.
"If it were not for Tunisia, none of this would be happening at this time or in this way," Entelis said.