Cairo, Egypt - While chants and songs boomed in the city's packed Tahrir Square, the epicentre of million-man marches that toppled two presidents in three years, mobs of sexual predators blended within the crowds, hounding female prey.

Although there are no official chronicles of the number of victims, local human rights groups claim more than 100 women were abused since protests started on June 28, with at least two cases of rape recorded.

"It's no longer accurate to refer to such assaults as mere sexual harassment. They are sexual terrorism," Fathi Farid, coordinator of local human rights group I Saw Harassmenttold Al Jazeera.

Millions of Egyptians, men and women, have taken to the streets since June 28, first to topple the country's first democratically elected civilian president, Mohamed Morsi, then to celebrate his ousting when the army decided to side with the demand for early elections.

I Saw Harassment, together with a number of other civil society initiatives, including Operation Anti-Sexual Harassment/Assault and Tahrir Bodyguards - which were founded due to the state's absence amid the epidemic of sexual violence the country has witnessed in recent years - ran a hotline and deployed volunteers in Tahrir Square and at other demonstration sites. Their aim was to thwart sexual assault attempts, especially as police forces boycotted the rallies, leaving protesters, especially women, vulnerable.

"Most of these assaults show that there is a fully organised crime at hand," Farid said. He described how mass sexual assaults began with five or six creating a tight circle around a victim, groping her body and tearing off her clothes - while yelling loudly that they're protecting her to keep help from entering the ring. "The circle immediately swells to dozens who all alternate at violating the victim, while her screams are muffled by theirs," he said.

Farid's description of the attackers' strategies matches those made by women who survived such assaults. According to the testimony of one unidentified survivor, posted on Nazra for Feminist Studies, another Egyptian initiative that aims to build a feminist movement, a mob tore her away from her male companions and violated her body while dragging her towards a deserted area, where they each planned to rape her individually. She managed to escape through pleading to one of the attackers who sympathised with her and snatched her away from the group.

Egypt has witnessed a staggering increase in sexual harassment rates over the past few years. A February 2013 study by UN Women and the Demographic Center showed that 99.3 percent of girls and women questioned had been subjected to harassment. Revolutionaries have claimed that since the 2011 revolution which toppled Hosni Mubarak, gangs have been paid to carry out such atrocities, in order to scare away female protesters and taint the reputation of Tahrir Square.

"Previously, a girl was at risk of being harassed if she was alone," said Farid. "A few days ago, a girl walking with four male companions was harassed by a mob. They beat up her companions and snatched her away. If this isn't terrorism what is?"

According to a statement jointly issued on July 3 by a number of Egyptian rights organisations, incidents of sexual assault reported during recent protests not only hit record highs, but "have been more brutal than the attacks that took place in January 2013" during demonstrations marking the revolution's second anniversary.

"I don’t believe any of the harassers were arrested," said Engy Ghozlan, a member of Operation Anti-Sexual Assault/Harassment. "The victimised girls usually prefer not to file lawsuits because they don't trust police forces, and because of social stigma," she added.

The rampant sexual attacks during the Tahrir Square protests highlight the failure of the government and all political parties to face up to the violence that women in Egypt experience on a daily basis in public spaces. Joe Stork, Human Rights Watch

Heba Morayef, Human Rights Watch director in Egypt, blames the increase in the number of mob sexual assaults on a state of impunity which "has led to a situation where the perpetrator feels that he won't be held accountable". The HRW report said Egyptian officials must be held accountable for the significant growth in the number of sexual assaults. According to Farid, only 24 incidents of sexual assault were officially reported in January 2013.

"The rampant sexual attacks during the Tahrir Square protests highlight the failure of the government and all political parties to face up to the violence that women in Egypt experience on a daily basis in public spaces," said Joe Stork, deputy Middle East director at Human Rights Watch.

Ghozlan agreed. "Regardless of the nature of the new regime and government, it is essential that speedy measures are taken to put an end to this epidemic once and for all," she said.

Farid, however, blames Morsi's administration for the surge in harassment. "The Muslim Brotherhood's regime, through its presidency and parliamentary councils as well as its media, has emboldened harassers through demonising anti-Morsi protests, especially women. This encouraged assaulters to feel that it was alright to ruin these women's lives."

Baheya Ya Masr is another local women's rights group. Its founder, Sally Zohney, said they had been facing violence for a long time.

"Sexual terrorism on female protesters is not new," she said. "It has been a tool since [the] Mubarak era, and is not based on individual random cases... In Egypt, we have a nationwide problem of sexual harassment and sexual assaults that made sexual terrorism in Tahrir go unnoticed by many."

It has become evident that harassers do not target women of any particular age, dress code or social criteria. According to Zohney, as well as Farid, recent victims of sexual assaults included young girls and older women. "What happened between June 28 till yesterday was outrageous. Over 150 women were physically and psychologically harmed forever," Zohney said.

"We have distributed about 8,000 mattress needles for free among female protesters," said Farid.

"We want to reach a point where an attacker would think a hundred times before harassing a woman, in fear that she might truly hurt him."