Battered and bruised, the 28-year-old was released hours later, after she said she was threatened and told "tonight, you're mine." But instead of going home, she walked right into a television studio.
"How can the same person who attacks an unarmed woman protect the nation? I was dragged and pulled from my hair. They hit me with batons in my stomach and my chest," Kamal, a member of the youth group April 6, told viewers of a popular chat show.
Images of women often in a lead role during the uprising that ousted President Hosni Mubarak in February resonated across the Arab world. Now women say they are being targeted; pictures of them being molested have fuelled anger at home and abroad.
In one video that has in the days since it was shot come to symbolize the abuse, army officers were shown dragging a woman by her black robe, worn by conservative Muslims, as she lay on the ground, revealing her blue bra. Then she was repeatedly kicked and clubbed. The image has gone viral on the Internet.
In response, thousands of women surrounded by men pledging to protect them demonstrated in Tahrir on Tuesday. "The women of Egypt are a red line!" they chanted, vowing to return this Friday for a mass demonstration.
Ordinary Egyptians and commentators have been outraged, piling pressure on the army and encouraging calls for it to hand power to an elected president sooner than June, when it has now pledged to hold the vote.
Equally worrying for the army, it has drawn a stinging rebuke from the United States, which gives $1.3 billion a year in military aid to Egypt.
"This systematic degradation of Egyptian women dishonors the revolution, disgraces the state and its uniform and is not worthy of a great people," U.S. Secretary of State Hillary Clinton said this week, some of the strongest language yet used by Washington against Egypt's new rulers.
Egyptian Foreign Minister Mohamed Kamel Amr rebuffed Clinton, saying Cairo accepts no interference in its affairs and described her remarks as a matter "not to be taken lightly."
Western diplomats said it was unlikely Washington would use its hefty Egypt aid budget as leverage. U.S. officials have so far praised the army for promising to hand power to civilians.
But the controversy adds to the clamor for change.
"The horrifying picture fills whoever sees it with nausea. No one could believe that this could happen to an Egyptian after ten months of a revolution that started in defense of dignity," commentator Fahmy Howeidy wrote.
"This picture has become an international scandal that puts any Egyptian to shame," he said in al-Shorouk newspaper.
In a conservative Muslim society, undressing a woman to show her chest and torso in public is taboo. The incident has become a dominating subject on TV shows, hogged the front page of newspapers and become a hot topic in the streets.
The army has sought to dampen down the dispute with what came close to an apology.
"This is our sister and I am sorry that this scene took place," General Adel Emara said in comments caught on video.
But he added: "The armed forces are innocent of systematic attacks, violence, destruction and hurting our women and girls. This soldier you see, he is from an Egyptian village, he cannot possibly deliberately harm his sister."
That and other qualified statements of regret have not defused the anger or quelled the mounting frustration at what many see as the army's impunity while it manages the transition.
But there are those in Egypt's still patriarchal society who don't believe women should be protesting at all. For many of them, a woman who sleeps outside the home, and above all in the tents that had been set up in Tahrir Square, has loose morals.
"The army, which has adopted a paternalistic attitude towards women since it has been in charge, has singled out women protesters for humiliation and degrading treatment," Hassiba Hadj Sahraoui, Amnesty International's deputy director for the Middle East and North Africa, said in a statement.
"The aim of behavior like this seems to be to deter women from demonstrating," Sahraoui said.
Earlier this year, 18 women were arrested when army officers also cleared Tahrir. Some of the detainees said they underwent abuse including forced virginity tests, beatings, electric shocks and strip searches while being photographed by male soldiers.
An unnamed general was quoted by CNN defending those events then, saying those girls were "not like your daughter or mine. We didn't want them to say we had sexually assaulted or raped them, so we wanted to prove they weren't virgins in the first place." A military official denied those comments were made.
The head of the Military Judicial Authority said on Tuesday that soldiers accused of involvement in the virginity tests would be put on trial, a pledge some critics saw as a bid to deflect criticism.
Activists say such abuse of women was also employed by Mubarak's security forces when protesters first took to the streets against his rule in 2005.
"Targeting female defenders of human rights is nothing but a continuity of Mubarak's methods," five Egyptian rights and feminist groups said in a statement.
"Using sexual violence against female activists cannot be seen outside attempts by the military establishment to marginalize women, prevent them from defending their rights and practicing them by participating in political life."
But the women protesting in Tahrir on Tuesday held up pictures of cases of abuse and vowed not to be silenced.
"What we witnessed is the least of what the military council has done to women," said Yasmine Hamdoon, a 32-year old fashion designer, adding that women protesters had been on the streets from the start and would not go back home now.
And for many Egyptian men and women, the picture of girl's bare torso, has become a rallying point.
"What happened was atrocious and it's unbelievable that the Egyptian army does this. This is not our army that humiliates women," Mohamed El Araby, a journalist. "The military council has to go and it will go."