CAIRO (AP) - They showed a military-style precision: Crowds of bearded Islamists proclaiming allegiance to Egypt's President Mohammed Morsi and chanting "God is great" as they descended on tents set up by anti-Morsi protesters outside the presidential palace, swinging clubs and firing rifles.
They set up a detention facility, interrogating and beating captured protesters.
The scene from bloody clashes outside the presidential palace a week ago hangs over Egypt's political crisis, as a daunting sign of how much more violent the confrontation could become between Morsi's Islamist supporters and the opposition that has launched a giant wave of protests against him.
Opponents of Morsi accuse his Muslim Brotherhood supporters of unleashing highly trained cadres — fired up with religious slogans — to crush their political rivals. They fear last week's violence was a signal that the Brotherhood will use force to push its agenda and defend its political gains in the face of a persistent protest movement demanding that Morsi withdraw a draft constitution largely written by his Islamist allies.
Ahead of a new mass rallies planned by both sides Tuesday, masked gunmen attacked anti-Morsi protesters in Cairo's central Tahrir Square before dawn, firing birdshot at them and wounding nine. It was unclear who was behind the attack, said security officials, speaking on condition of anonymity because they were not authorized to talk to the press.
Officials from the Brotherhood and its political party deny using violence to quell critics. They say its supporters last week were defending the palace when police failed to do so, though by the time of the violence the only protesters outside the palace were around 100 conducting a sit-in in the tents.
Brotherhood officials accuse former regime supporters and paid thugs of waging an organized campaign to topple Islamists from power and point to a series of attacks on Brotherhood offices the past weeks. Morsi supporters say they suffered more deaths and injuries during last Wednesday's bloody clashes that left at least eight people dead.
But testimonies and videos that have emerged from the nearly 15 hours of street clashes last week show an organized group of disciplined Islamists, working in units and carrying out military-type exercises as they broke up the tent sit-in at the palace.
Opponents of the Brotherhood frequently accuse the group of running a "militia." The group is known for its tight discipline, and it acknowledges that many of its young members undergo organized martial arts training — but it vehemently denies forming any militias.
Tharwat el-Kherbawy, a former Brotherhood member and now an opponent of the group, said the Brotherhood's central organizational doctrine — calling on members to "hear and obey" their leaders — gives it a military-like structure.
When the Brotherhood met a stronger than expected protest movement, "they had no hesitation in hastening to implement their ideas and resorting to violence," he said. "If their empowerment project is facing resistance, this resistance must be quelled."
During last Wednesday's fighting, nearly 140 anti-Morsi protesters were detained, tortured and interrogated at a makeshift center set up by the Brotherhood along the walls of the presidential palace, according to witnesses. The detained protesters were filmed making forced confessions that they had received foreign funds, according to some who were held and an Egyptian journalist who snuck into the site.
One of the victims, Yehia Negm, an Egyptian diplomat, told The Associated Press he was dragged on the ground to the center where he was beaten. He is suffering from multiple injuries in the head, eye, nose, and ribs from beating and had remains of pellets in his forehead from gunfire during the clashes.
"When they found my ID that says a diplomat, they started accusing me of working with security agencies, of being a spy and of serving foreign countries," Negm said. "They rained beatings down on me. They started yelling at me, saying, 'You infidels, you want to burn the country down, you are not Muslims.'"
Around 20 Islamists manned the center, made up of metal barricades erected against the palace wall, said Mohammed Elgarhy, a local journalist with the daily Al-Masry Al-Youm who snuck into the detention center and spent nearly four hours there. Among them was a man he recognized as a well-known Brotherhood lawyer and two others he overheard speaking with a Brotherhood leader. The others, who he said he believed were Brotherhood members, carried out the beatings and interrogations.
"The Brotherhood were carrying out the job of the Interior Ministry," Elgarhy told AP. "They would arrest anyone they suspected and bring here ... asking them questions such as who paid for you to come here."
Troops from the Central Security Forces guarded the site, but did not interfere, he said.
The violence came a day after hundreds of thousands marched on the palace in Cairo's upper middle