Several thousand protesters marched toward Egypt's ministry of defense and headquarters of the country's military rulers in a rare rally Friday following reports of scuffles between protesters and soldiers in other cities.
Armored vehicles and hundreds of military police blocked the road leading to the defense ministry, however, preventing nearly 4,000 protesters from advancing any further.
The standoff continued into the early hours of Saturday. It blocked traffic at a busy square across the city from Tahrir square, where several hundred die-hard activists have camped out for more than two weeks demanding faster change by the military.
Many protesters have grown mistrustful of the military, accusing it of dragging its feet in bringing former regime officials to trial.
More than five months after mass street demonstrations drove President Hosni Mubarak from power, many Egyptians worry that their "revolution" has stalled.
Fewer protesters have been turning up during the day. Searing summer heat and a growing weariness among some with continual protest diminished the large numbers seen in the last weeks. Several hundred have camped out in Tahrir square and other cities for nearly three weeks demanding faster change.
By late Friday, reports of scuffles between protesters and the military in the coastal city of Alexandria reached Tahrir square. Witnesses said scuffles broke out between protesters and the military at their headquarters in Alexandria, following attempts by some protesters to block traffic and take their grievances inside the building.
The reports drove hundreds of protesters out of Tahrir square, marching toward the defense ministry where the military council's offices are based. The crowd picked up along the road but military deployment blocked the road to the ministry.
The late night rally prompted a quick response from the military.
The council denied in a statement the use of violence against protesters and accused activists of driving a wedge between the people and the military. The council singled out the April 6 group, one of the largest activist groups in Egypt and a leading movement behind the protests that forced Mubarak to step down.
"The Supreme Council of the Armed Forces urges the public to exercise caution and not to be drawn into this suspicious plot that aims to undermine Egypt's stability," the statement said in unusually strong language.
The rally comes on the eve of the 59th anniversary of the military coup that toppled the monarchy in 1952. Protesters had planned a large rally outside the military council during the day Saturday to press for their demands and condemning the use of military trials against civilians.
State TV cited a witness early Saturday as saying the military fired into the air to disperse the crowd, but the bulk of the protesters held their ground.
While Mubarak, his sons and a number of his associates have been in custody, protesters see traces of his regime throughout the government.
Earlier Friday, a smaller number turned up in Tahrir for what they called "the Friday of decisiveness." It was a day after the prime minister replaced nearly half his Cabinet in a nod to demands from the protesters that most activists dismissed as not going far enough.
"The military council is against the revolution, and we're here to put pressure on them to stay with the revolution," said Ahmed al-Sharawi, 21, an engineering student who has been camped out in Tahrir. "If we go home, the revolution will fail," he said.
Others come to the square for different reasons, not least the carnival-like atmosphere that has taken over.
Activists have blocked traffic on all streets leading in, turning the large interchange at Cairo's heart into a pedestrian-zone _ a rare luxury in this overcrowded city of 18 million, famous for it reckless drivers and traffic jams.
Inside, vendors have wheeled in carts or set up shop on the sidewalks, selling pretzels, fruit, plastic guns and revolution-themed T-shirts, headbands and wall clocks. Cold drinks are the biggest seller, necessary in a season when midday temperatures regularly top 100 Fahrenheit (38 Celsius).
Also limiting the protests' size was the decision by the Muslim Brotherhood, Egypt's best organized political force, not to participate.
Some who come for the atmosphere in Tahrir oppose the sit-in.
"I don't like the way the tents look," said Haisam al-Halawani, 28, who strolled in Friday afternoon with his wife Rasha. "Sure, people should come and say what they want, but then they should go home. We don't need all these tents."
Still, the pair visits the square weekly, to people-watch, listen to speeches and have a snack and a cold drink.
Al-Halawani agrees with many of the protesters' demands, especially that former regime officials face prosecution, but he said the protesters expect too much, too fast.
"Not everything will change in one day," he said.
In another square across town, a few hundred protesters calling themselves "the silent majority" held a counter-demonstration in support of the military council.
Inside the Tahrir tent camp, al-Sharawi, the engineering student, listed the reasons he's been sleeping in a tent in a traffic circle for more than two weeks: He distrusts the military, wants to see former regime officials tried and said the Cabinet is stocked with Mubarak associates.
He and his fellow tent-dweller Mohammed Shaban rejected the idea that other Cairenes say blocking traffic impedes work.
"If they want to work, they need to protest with us so we can get all our demands and go home," said Shaban, 22.
In the meantime, the men live on pita bread and preserved cheese, do their laundry in a bucket and wash at a nearby mosque.
"We were in the army, where they give you a cup of water and say, Take a bath! So we're used to it," said al-Sharawi, recalling the compulsory stint in the military that Egyptian young men must serve.
They say they'll remain until "the revolution" is complete.
"Other people bring KFC with them when they protest," he said. "Not us. We don't want food or money. If we get all of our demands, Egypt will be richer than America."