The men on motorcycles led the way, speeding down the main boulevard in Mohandessin on a mission.
They beeped their horns, traced figure eights on the pavement and flashed two-finger signs of peace.
Thousands of demonstrators fell in behind them like an army, chanting support for their President.
Some kissed Egyptian flags, or glossy photos of Hosni Mubarak. Others brandished sticks and pistols. Many of the signs were preprinted.
One of the most striking ironies of this uprising is that before Mr. Mubarak made an emotional appeal on Egyptian state television Tuesday night to end the chaos, the demonstrations in Cairo had largely been peaceful.
In the wake of that speech, pro-Mubarak protesters have emerged in throngs as a potent and unpredictable force.
It is unclear who, exactly, is mobilizing them, and equally uncertain how far they will go to protect the status quo.
Their presence is having a profoundly destabilizing effect on the streets, and more broadly, on how Egypt's future will unfold.
Yesterday, the Egyptian army succeeded in routing the pro-Mubarak crowds away from Tahrir Square, the scene of deadly clashes in recent days with anti-Mubarak demonstrators.
It was just one of the signs that the army was asserting itself with fresh force, highlighting its growing influence, both politically and on the street.
Pro-Mubarak demonstrators were stopped at the edge of the Nile River and redirected.
"We are the true Egyptians," said Mohammed Aleem, a 42-year-old factory worker, who wore a headband that matched the Egyptian flag wrapped around his shoulders.
"He is our President. He is the symbol of our country. He is being treated badly by the foreigners and we must fight for him," Mr. Aleem said.
He blamed Western leaders and foreign journalists for fuelling the protests in Tahrir Square and other parts of Egypt.
For days, anti-Mubarak protesters have accused the Egyptian government and its security forces of orchestrating violent protests like the one yesterday in Mohandessin.
Some anecdotal reports suggest that supporters are being bussed in from outside Cairo, being given up to $100 a day to march in favour of Mr. Mubarak.
An Egyptian police officer, who did not want to be identified, said that many of the demonstrators had been paid off by Mr. Mubarak's National Democratic Party, dismissing the notion that they were simply average Egyptians rising up to support Mr. Mubarak.
"These are not regular people," he said. "Regular people are inside their homes."
Mr. Mubarak's regime has been accused in the past of using hired thugs in crackdowns, a strategy that has been well-documented by human-rights groups such as Amnesty International and Human Rights Watch.
Around the tense perimeter of Tahrir Square, anti-Mubarak demonstrators were shaking down anyone seeking to enter.
Those who were suspected of being pro-Mubarak agitators were handed over to a volunteer "people's protection force" for questioning.
"They are sending in people to spy on us," said Miriam Mansour, one of the women who were conducting the searches.
She displayed three police identification cards she said were confiscated from some of the infiltrators, suggesting collusion between the pro-Mubarak forces and Egyptian police.
Provocateurs who were caught were made to sit in the centre of the square, in a public display of shame.
In Mohandessin yesterday, Egyptian police clashed with the pro-Mubarak demonstrators, fighting off a mob that attacked two Globe and Mail journalists with sticks and fists by firing warning shots into the air.
The pro-Mubarak demonstrators had become noticeably more aggressive. The crowd was made up entirely of young men, searching for a target to vent their fury.
Earlier in the week, things were different. Some elements among the pro-Mubarak demonstrators appeared to be sincerely frustrated with the prospect of their President being ousted from power so suddenly.
Indeed, pro-Mubarak demonstrations on Wednesday appeared to be much more genuine and peaceful.
Tens of thousands of demonstrators filled the Mustafa Mahmoud Square, cheering for their President and denounced the opposition.
They expressed anger at the international media for its coverage. "The world thinks the people in Tahrir Square speak for all Egyptians. They don't," said Sarah Ali, a 28-year-old protester.
She was proudly holding a sign that read: "Mubarak is the Fourth Pyramid of Egypt."
With a report from Patrick Martin