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Protesters holding sticks and wearing helmets and makeshift body armor stand behind mounds of sandbags, tires and brick walls. They change guards every two hours to ensure they stay alert.

With Egypt's military-backed government signaling a crackdown is imminent, supporters of ousted Islamist President Mohammed Morsi are taking no chances with security at their two protest camps in Cairo.

On Wednesday, the Cabinet ordered the police to break up the sit-ins, saying they pose an "unacceptable threat" to national security.

Interior Minister Mohammed Ibrahim said the order will be carried out in gradual steps according to instructions from prosecutors. "I hope they resort to reason" and leave without authorities having to move in, he told The Associated Press in a telephone interview.

Ahmed Sobaie, spokesman for the Muslim Brotherhood's political arm, the Freedom and Justice party, derided the Cabinet decision as "paving the way for another massacre."

"The police state is getting ready to commit more massacres against the innocent, unarmed civilians holding sit-ins for the sake of legitimacy," he said.

Organizers are portraying the sit-ins outside the Rabaah al-Adawiya mosque in eastern Cairo and a smaller one across the city near Cairo University's main campus as evidence of an enduring support base for Morsi's once-dominant Muslim Brotherhood.

The fundamentalist group has long been one of the most powerful political forces in Egypt, even during its decades in the opposition to autocratic leader Hosni Mubarak, himself ousted in a popular uprising in 2011.

But after a series of election wins, including Morsi's presidential victory last year, the group has fallen from popular favor. Morsi was ousted in a July 3 military coup after millions took to the streets to call for him to step down because he granted too much influence to the Brotherhood and failed to implement much-needed social and economic reforms.

The Brotherhood has so far refused to cooperate with the country's interim leaders, whom it calls "traitors," or participate in a military-backed fast-track transition plan to return to a democratically elected government by early next year. Instead it tries to keep thousands of supporters camped out in tents decorated with photos of Morsi, occupying a cross-shaped intersection facing the mosque.

Authorities have already cracked down on the organization, arresting Morsi and other senior leaders. On Wednesday, Egyptian prosecutors referred three top leaders of the Muslim Brotherhood to trial for allegedly inciting the killing of at least eight protesters last month outside the group's Cairo headquarters.

Clashes outside the camps between security forces and protesters have left more than 130 people dead altogether.

At least six makeshift gates have been erected as the sole entry points to the Rabaah encampment, with dozens of protesters standing guard, checking IDs, searching bags and patting down visitors.

Once through the gates, posters with photos of Morsi and slogans calling him the "legitimate president" are plastered on tents, corners and light poles while giant loudspeakers play some of his fiery speeches and women chant "Morsi is my president."

The overwhelming majority of the protesters echo the demands of the Brotherhood leaders still free: Reinstate Morsi, reverse all measures taken by the military, including the suspension of the disputed constitution and the disbanding of the Islamist-controlled legislature. Only if these demands are met, they insist, would they halt the two Cairo sit-ins and the demonstrations, which has attracted crowds of up to 20,000.

But privately, the Rabaah protesters acknowledge that their sit-in is their last bargaining chip in the face of a fierce onslaught by the military and loyal media that label the encampment as a hideout for terrorists. Islamic militants also have been stepping up attacks against security forces in lawless areas in the Sinai Peninsula, raising fears that extremists could exploit the anger over Morsi's removal to spread insurgency.

"We will not have a life outside of here," Shawki Hamed, a schoolteacher in his early 40s, said while squatting cross-legged inside one of the hundreds of tents now dotting the site. "We have seen with our own eyes the way they manipulate the truth. They attack us, then portray us as terrorists. ... If Morsi is not back, our life will be a series of humiliations and fabricated charges."

The comments reflect the depth of feeling among Morsi's supporters and the Brotherhood's continued ability to mobilize its base with long-honed organizational skills that combine pragmatism and religious piety.

While "victory or martyrdom" seems to be a favorite punch line for a majority of protesters, Gamal Radwan, a Muslim Brotherhood member from the industrial city of Mahallah in the Nile Delta, said: "At the end, we must reach the negotiating (table). There must be concessions and a meeting point. ... Now this is the time for pressure. You press here and I press there until we reach a point that is satisfactory to all of us."

Standing outside his tent with a prayer rug in hand ready to head for the noon prayers, he said the Brotherhood should not offer concessions from the outset.

"You give me something and I give you something but there are basics that I can't give up. ... I am not talking here about Morsi," he said. "I can't return to the injustices, the state security taking away my freedom."

Martyrdom, he added, is a "noble mission for all Muslims ... but if I can achieve my goal without losing my life, why not?"

Lists of the names and personal belongings of slain protesters are on display inside the encampment's "Documentation Center for the Massacres in Egypt's Squares." Among the exhibits in the large tent are photographs and personal belongings of those killed. One exhibit is a blood-stained gray shirt that belonged to a slain protester. It is emblazoned with, "He left his shirt to you. Don't leave his president."

During a funeral, a weeping wife took the stage at Rabaah to recount the last words of her late husband, telling the crowd how he saw the Prophet Muhammad in his sleep and was invited to hold prayers with him.

"You think I am lying? I swear to God, no," the wife said as she wept. Her words triggered chants of "No God but Allah" while many of her listeners held back tears.

Photos of bloodied faces of slain protesters are posted in every corner and tent. Some banners provide information such as the dead demonstrator's background, hometown and profession.

"The more blood spilled, the more people join in," said Saad el-Husseini, a former governor of Kafr el-Sheikh province and prominent Muslim Brotherhood figure. The security forces "are very stupid because they don't take gradual measures in their repression."

But the group is facing a bigger challenge than state repression: loss of popular support. Last week, millions marched in demonstrations giving a mandate to charismatic military chief Gen. Abdel-Fattah el-Sissi — upon his request — to confront "terrorism" and potential violence.

Losing public sympathy in Egypt, the Rabaah tent city is plastered with signs in English appealing to the outside world. A large banner reads: "No to military rule." Many tents bear signs that suggest the protesters represent a diverse cross-section of society, such as "Veterans for Morsi," or "Teachers for Morsi" or "Actors for Morsi."

Heading to a march Tuesday, a woman covered from head to toe except for her face carried a sign that read: "Seculars for Morsi."

Signs in Arabic give a different message altogether.

"Oh, Sissi, the Jews and the Christians will not be satisfied unless you follow their religion," said one. A picture for Morsi leading prayers was titled, "For this, they fought you our beloved one."

Protester Manal Abdel-Aziz said she left her family to spend nights in tents with other women from the Muslim Brotherhood because "this is a coup to get religion out. ... They don't want Islam, they want a secular state. ... They got money from America and Israel to harm the religion."