Updated 2:21 p.m. ET
Protesters and regime supporters fought in a second day of rock-throwing battles at a central Cairo square while new lawlessness spread around the city. New looting and arson erupted, and gangs of thugs supporting President Hosni Mubarak attacked reporters, foreigners and rights workers while the army rounded up foreign journalists.
The government increasingly spread an image that foreigners were fueling the turmoil and supporting the tens of thousands in the street who for more than 10 days have demanded the immediate ouster of Mubarak, this country's unquestioned ruler for nearly three decades.
Complete Coverage: Anger in the Arab World
"When there are demonstrations of this size, there will be foreigners who come and take advantage and they have an agenda to raise the energy of the protesters," Vice President Omar Suleiman said in an interview on state TV.
Egyptian army tanks and soldiers cleared away pro-government rioters and deployed between them and protesters seeking the fall Mubarak, moving to halt violence as the prime minister Thursday for the assault by regime backers that turned central Cairo into a battle zone.
CBS News correspondent Mark Strassmann reports that Mubarak's government was almost certainly responsible for deploying the waves of attackers to lay siege to the camp in Tahrir Square. They were well-organized. And on some of them, protestors later found government or police ID's.
"A day after asserting he would not run again for office, Egypt's president re-asserted his authority - tried to crush this popular dissent - reminding protestors why they had taken to the streets in the first place," notes Strassmann.
Gunfire and clashes continued in the Cairo square at the center of Egypt's anti-government chaos, while new looting and arson spread around the capital. Wounded people were carried out Tahrir Square, where Mubarak supporters and opponents have been fighting for two days. At least eight people have been killed since the clashes erupted Wednesday afternoon. More than 1,000 have been injured.
CBS News Khaled Wassef reports that another person was killed - and three more injured - by gunshots fired by snipers positioned on buildings surrounding Tahrir Square Thursday. An eyewitness told Al Jazzeer that the slain protester died of a bullet in his head and that the shooting was caught on videotape.
Prime Minister Ahmed Shafiq said the attack Wednesday on the anti-Mubarak protesters was a "blatant mistake," acknowledged it was likely organized and promised to investigate who was behind it.
Vice President Omar Suleiman said in elections later this year, in the latest concession to anti-government protesters.
It was widely believed that Mubarak was grooming his son Gamal, 46, to succeed him despite significant public opposition.
Egypt's state news agency also reported that the prosecutor-general has of the government that was sacked over the weekend, including the interior minister who was responsible for police.
The prosecutor-general said he ordered the same restrictions against a senior ruling party official until security is restored in the country.
But the gestures appeared likely to be drowned out by the chaos around Tahrir, or Liberation, Square, which for the past 10 days has been the center of the unprecedented movement demanding Mubarak's immediate ouster. Protesters accuse the regime of organizing a force of paid thugs and police in civilian clothes to attack them Wednesday afternoon, sparking the violence that still raged after nightfall Thursday.
In an interview with state television broadcast Thursday, Suleiman vowed to release detained all youth and advocacy workers who had participated in the protests without inciting violence. But he also vowed punishment for those currently fighting - and for those behind the pro-Mubarak gangs that sparked violence Wednesday.
Suleiman called Wednesday's events in Tahrir Square a conspiracy, Wassef reports, and said the government would punish those who "cooked" the conspiracy. He said that investigations will show who pushed the gangs to go to Tahrir Square and that the responsible parties undermined the work of President Mubarak in recent days.
Suleiman, who Mubarak recently appointed as the first vice president during his 30-year rule, said the protesters have legitimate and acceptable demands and that the government was happy to listen - but alluded to foreign interests infiltrating protest groups as well.
The vice president then spoke about a process of constitutional changes - revisions, but not a complete overhaul - that would need to take place before new elections in September.
Lawlessness that had largely eased since the weekend flared anew. A fire raged in a major supermarket outside Sheikh Zayed, a suburb of the capital, and looters were ransacking the building. A residential building neighboring a 5-star hotel on the Nile River corniche was also ablaze, blocks away from Tahrir. Other fires erupted in the Cairo district of Shubra, north of the center, security officials said, speaking on condition of anonymity because they were not authorized to talk to the media.
In the morning, the military took its first muscular action to halt the fighting after standing by without interfering since the fighting began. They moved after heavy barrages of automatic gunfire over the course of two hours before dawn killed five protesters in a serious escalation.
Four tanks cleared the highway overpass and several hundred soldiers on the streets below lined up between the two sides, pushing the pro-government fighters back and blocking the main battle lines in front of the famed Egyptian Museum and at other entrances to the square. For several hours after, more protesters streamed into the square to support those who had fought through the night.
But when clashes resumed in the afternoon, soldiers disappeared from the streets, moving inside their tanks and armored vehicles without intervening again. Every once in a while, protesters would wrestle a Mubarak supporter to the ground, search him for an ID, then raise the card in the air to prove he was a police officer or ruling party member.
The anti-Mubarak movement has vowed to intensify protests to force the president out by Friday. In a speech Tuesday night, Mubarak refused to step down immediately, saying he would serve out the remaining seven months of his term - a halfway concession rejected by the protesters.
In Washington, U.S. State Department spokesman P.J. Crowley condemned what he called "a concerted campaign to intimidate international journalists in Cairo."
Pro-government mobs beat foreign journalists with sticks on the streets outside downtown Tahrir Square, the epicenter of the protests. Dozens of journalists, including ones from The Washington Post and The New York Times, were reported detained by security forces. One Greek print journalist was stabbed in the leg with a screwdriver, and a photographer was punched in the face by attackers who smashed some of his equipment. The Arabic news network Al-Arabiya pleaded on an urgent news scroll for the army to protect its offices and journalists, and Al-Jazeera said two of its correspondents were attacked.
Human rights activists were also targeted. Military police stormed the offices of an Egyptian rights groups as activists were meeting and arrested at least five, including one from the London-based Amnesty International and another from New York-based Human Rights Watch, the groups said.
Al-Jazeera kept its camera crews away from the square and instead relied on reporters of Arab descent who had flip cameras and tried to do their work by blending in with the crowd, said Al Anstey, the network's managing director.
"It's a very, very challenging situation," Anstey said. "But it's history in the making."
The army also , possibly for their own protection.
Many Western journalists were attacked by apparent Mubarak supporters on Wednesday, with both Strassmann and CBS Evening News anchor Katie Couric and their crews meeting hostility for the first time since the Cairo protests erupted more than a week ago.
Mob gangs are likely involved in an organized campaign targeting the foreign reporters, Wassef reports. A U.S. intelligence source told CBS News correspondent Lara Logan that the Egyptian secret police may be behind the organized attacks on media.
The attacks appeared to reflect a pro-government view that many media outlets are sympathetic to protesters who want Mubarak to quit now rather than complete his term.
Tweeted that Mubarak supporters near Tahrir Square were "very hostile," preventing a CBS crew from shooting video and punching a photographer.
(Watch protesters crowd around Couric and her camera crew at left)
Strassmann near Tahrir Square.
Shafiq's highly unusual apology and the army intervention suggested at least some in the regime want to step back from Wednesday's dangerous turn - the first outbreak of street violence between the two sides in what is now 10 days of unprecedented protests demanding Mubarak, unquestioned leader for nearly 30 years, quit power.
The notion that the state may have coordinated violence against protesters, whose vigil in Tahrir Square had been peaceful for days, raised international outrage, including a , which has considered Egypt its most important Arab ally for decades, and sends it $1.5 billion a year in aid.
"If any of the violence is instigated by the government, it should stop immediately," said White House Press Secretary Robert Gibbs.
A sense of victory ran through the protesters Thursday after they succeeded in keeping their hold on the square and pushing back their attackers.
Many dismissed the government concessions, which would have been stunning only a month ago, and said they wanted nothing less than Mubarak to go now.
"We have gone beyond these demands a long time ago," said Waheed Hamad, a 40-year-old schoolteacher among the protesters. "What we need is something bigger. And the road is still long." He said the attacks on protests would only make them grow. "Blood is the fuel of the revolution."
Bands of Mubarak supporters moved through side streets around Tahrir, trading volleys of stone-throwing with the protesters and attacking cars to stop supplies from reaching the protest camp. One band stopped a car, ripped open the trunk and found boxes of juice, water and food, which they took before forcing the driver to flee.
The Mubarak backers seethed with anger at a protest movement that state TV and media have depicted as causing the chaos and paralyzing businesses and livelihoods. "You in Tahrir are the reason we can't live a normal life," one screamed as he threw stones in a side street.
The anti-Mubarak youths posted sentries on the roofs and balconies of buildings around the square to raise the alert of any approaching attackers and rain stones on them. Other lookouts in the streets banged metal poles against pedestrian barriers alarm when they sighted incoming Mubarak backers.
One sentry waved his arms in the air like an airport runway traffic controller, directing defenders carrying piles of stones as ammunition to a side street to fend off an assault. But then another sentry waved a hand across his chest horizontally in a new signal. The crowd understood: false alarm, and they melted back into the square.
Shafiq's promise to investigate who organized the attack came only hours after the Interior Ministry issued a denial that any of its police were involved.
"I offer my apology for everything that happened yesterday because it's neither logical nor rational," Shafiq told state TV. "Everything that happened yesterday will be investigated so everyone knows who was behind it."
The anti-Mubarak movement has vowed to intensify protests to force the president out by Friday. In a speech Tuesday night, Mubarak , saying he would serve out the remaining seven months of his term - a halfway concession rejected by the protesters.
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