UN report said 99.3% of females had been subjected to sexual harassment in Egypt
The trial began on Wednesday of 13 Egyptian men accused of taking part in mob sexual assaults on women during rallies including celebrations this month for the election of the new president, who has demanded authorities crack down on the crime.
The men have been charged over five cases this year involving nine women who were stripped, sexually assaulted and beaten by gangs of men around Cairo's Tahrir Square, the heart of the 2011 revolution and a focus for gatherings.
After the attack on the woman on June 8, during a rally to celebrate the victory of Abdel Fattah al-Sisi, the president called on citizens "to reinstate the true spirit of ethical and moral values in Egyptian society" and the state to "robustly enforce the law".
Violent group attacks on women in crowded public places have been rampant at the protests and gatherings that have taken place since the 2011 uprising that toppled Hosni Mubarak.
Sexual assaults are often hushed up by the victim's family as they try to salvage her reputation. When women do come forward, they face a male-dominated police force whose members are not adequately trained to deal with such sensitive cases.
A UN report on women last year said 99.3 percent of women and girls had been subjected to sexual harassment in Egypt.
Some attacks in which women can be seen naked, injured and being dragged through the streets have been captured by witnesses on mobile phones and spread online, causing outrage.
A video of the attack against one woman appeared online and, asked about it on air, a television presenter giggled and said the people were simply enjoying themselves. Her response caused an outcry and Sisi visited the victim in hospital.
Speaking before the trial, the lawyer representing the woman and her daughter who were attacked and suffered severe injuries called for the maximum sentence of life in prison to be imposed.
The lawyer, Hatem al-Saeed, said: "I call these people criminals. This is not harassment. This is a crime."
The men are charged with a range of offences ranging from kidnapping, sexual assault and bodily harm to attempted murder.
The prosecutors charge forms suggested many of the women were lured away from the crowd by men feigning to protect them from harassment, before being surrounded and attacked.
The father of one of the victims said the 19-year-old student had lost the use of her left eye after being struck with a belt buckle during the assault that took place when she became separated from her parents and friends during a pro-Sisi rally.
"I want to them to be punished justly. I want the maximum sentence for my daughter and the other girls. Even today, she wakes up screaming in the night and when I ask her what's wrong she says 'daddy, I remembered what happened'."
The defendants appeared in a cage to the side of the Cairo court room, which was packed with the families of the victims.
They swore their innocence, some of them holding aloft copies of the Koran. A defence lawyer told Reuters one of the alleged victims, a women's rights activist, had fabricated the incident to create a media furore.
After the charges were read, the judge closed the session to the public due to the sensitive nature of the case. The next hearing in the case will be held on June 29.
Egypt issued a new law this month punishing sexual harassment with six months or more in jail or fines of at least 3,000 pounds ($420). A Cairo court sentenced a man to one year in jail on Saturday for harassing a woman.