Mohamed Abd El Ghany / Reuters

A man redraws the graffiti along Mohamed Mahmoud street, a day after the walls were believed to be painted by government workers to cover former graffiti, in downtown Cairo on Wednesday.

Under cover of darkness, a few municipality workers quietly began to paint over an icon of Egypt's revolution: a giant, elaborate public mural on the street that saw some of the most violent clashes between protesters and police over the past two years.

The mural, stretching three blocks along a wall off Cairo's Tahrir Square, has been a sort of open-air museum of the history of the revolution and its goals — with "martyr" portraits of slain protesters, graffiti, jokes, freedom slogans and pharaonic, Muslim, Christian and nationalist images to show Egypt's mixed heritage and a history of struggle.

Analysis: 'Manufactured outrage' behind Middle East protests

Word of the whitewash quickly got out. A number of progressive, young revolutionaries showed up to defend the murals. In the dead of night, they began to film the workers as they painted under the guard of police, hoping to embarrass them. They talked with the painters about what the murals meant.

The scene on Mohammed Mahmoud Street in the early hours Wednesday was a small but telling counterpoint to last week's angry protests at the U.S. Embassy, led by ultraconservative Islamists protesting an anti-Islam film. Those protests took place only a few blocks away on another street off Tahrir.

Together, the scenes point to the competition over the identity of the new Egypt, over what the country stands for now and what can be expressed.

PhotoBlog: Graffiti artists target whitewashed walls and the president

The mix of largely secular activists who launched the revolt against longtime leader Hosni Mubarak last year say the "revolution" is still continuing, until the country breaks with its authoritarian past and brings freedom and economic justice.

The Islamists, who rode to power after Mubarak's ouster, have their own vision for Egypt, which they say should adhere to an "Islamic identity" as they define it and preserve traditions.

'Erasing history'
The government says it has launched a campaign to beautify Tahrir Square, the center of anti-Mubarak protests. But activists saw it as a government attempt to blot out the calls for continued revolution and to assert that a new and stable system is now in place, under elected Islamist President Mohammed Morsi.

"They are erasing history," Gamal Abdel-Nasser, the father of a 19-year old killed during the early days of anti-Mubarak protests, said as he stood at the mural street. "This is not my government. It doesn't represent me."

Slideshow: Anger over film spreads throughout Muslim world

Akhtar Soomro / Reuters

Protests ignited by a controversial film that ridicules Islam's Prophet Muhammad spread throughout Muslim world.

Launch slideshow

And for some, repainting the wall just underlined the feeling that the Islamists have snatched the prizes of the revolution.

"This is not about the wall. It is about everything happening in Egypt," said Nazly Hussein, one of the first to arrive at the scene to protest the paint job with a camera, live streaming the workers as they covered murals. "It is about territory they took away from us."

The anti-film protests, she said, showed how under Morsi's three-month-old rule progressives were still having to fight for basic issues like freedom of expression. She pointed to government crackdowns on strikes and the recent sentencing of a Coptic Christian to six years in prison for insulting the Prophet Muhammad and Morsi. Still unaddressed are bigger goals of the revolution.

"This is about lowering our ceiling. Our real battle is about freedom. Now we are fighting about the right to insult the president or not," she said. "All those on the wall died for bread, freedom and social justice," she said, referring to the martyr portraits.

Egypt issues arrest warrants for Terry Jones, Coptic Christians over anti-Islam video

After the intervention by activists, the municipal workers stopped the whitewashing at daybreak with only half the mural painted over. Graffiti artists moved in to start putting new images on the now white walls. By late Wednesday night, the municipal workers hadn't returned to finish their job, amid a media uproar over the mural erasure.

The first drawing to go up was a portrait of a young man sticking his green tongue as a taunt. "Do it again! Erase, you cowardly regime," was written beneath it.

'A worse dictatorship'?
Graffiti artist Ahmed Nadi painted a new caricature of Morsi, smiling smugly, with the words, "Happy now, Morsi?"

Ali Saleh, a 53-year old security guard at a nearby school, said the murals must stay as a reminder to authorities of the mistakes they committed.

"If we give up the graffiti, this would be the first nail in the coffin," he said. "We are in for a worse dictatorship than Mubarak's."

The sense of progressives that the wall is their territory is deepened by its location. Mohammed Mahmoud Street saw dozens killed late last year and early this year as security forces repeatedly tried to crush youth protesting against police brutality and the military rule that followed Mubarak's fall. Morsi's Muslim Brotherhood and other Islamists refused to join the protests.

How rap music fueled the Arab Spring

Several of the activists accused the government and other Islamists of focusing on anger over the film to distract from the lack of real change since Egypt's first free election over the summer brought Morsi to power.

"Is this what will take Egypt forward now? Erasing the graffiti?" a school student in his teens shouted as the artists began to refill the wall with images.

"So long as we can't talk freely in this country, we still need walls to paint and songs to write," said Amr, an 18-year old commerce university student, refusing to give his last name because of security officers who remained nearby. "We are trying to be free. They don't want us to go down this road. They don't want a thinking people."

'Can't have a revolution every day'
Many Egyptians, however, say they just want stability after more than 20 months of turmoil. Some residents of the Mohammed Mahmoud area were happy to see the murals go, ending a reminder of the battles on their doorstep.

"This is ugly," said Nour Nagati, referring to the graffiti of a man with his tongue out. "Paint me a flower, paint me a tree. This is a symbol of stability. But this provocation will only perpetuate provocation."

Another resident in the area, who says he lived in Germany for 20 years and is an agricultural engineer, objected to the new graffiti artists over the words "cowardly regime" they had just scrawled on the wall.

"Why should I wake up and find this profanity scribbled on the walls. I am Egyptian. This is not my culture. This is only for the Westerners," said the man, who wore the small beard of a conservative Muslim. He refused to give his name.

But the lines are not black and white in Egypt: Age can be as much a factor as ideology. A younger man in his 30s with the even longer beard of an ultraconservative Islamist interjected and defended the murals.

"Why the distinction between West and East when it comes to freedom of expression? There is no doubt that whoever represses and breaks up protests is a coward."

The engineer looked at him in surprise, thrown by the idea of an ultraconservative defending graffiti.

"You're mixing everything up!" he cried.

Abdel-Karim Abu Bakr, a passer-by, said the time for using the walls for protest was over.

"We had a revolution, we changed the regime. Let's calm down ... We can't have a revolution every day."

More world stories from NBC News:

• Analysis: 'Manufactured outrage' behind Middle East protests
• Arctic sea ice reaches new low
• Ultra-Orthodox Jews confront child sex abuse
• State Department: No secret plan to invade Canada
• Russia tells US: We don't want your aid money
• US Muslims denounce both violence and anti-Islam film
• Protesters: 'The Diaoyu islands belong to China!'
• Stay informed: Sign up for our newsletter

Follow World News from NBCNews.com on Twitter and Facebook