Egyptian security forces have stepped up sexual violence since the military overthrew the country's first freely elected president in 2013, a human rights group alleged on Tuesday.
Victims include members of NGOs, students, women and those perceived as "endangering the moral order," the International Federation for Human Rights (FIDH) said in a report.
It was not possible to confirm the allegations. Spokesmen for Egypt's Interior Ministry and military were not available for comment despite several attempts to reach them.
Egypt's human rights record has come under scrutiny since then-army chief Abdel Fattah el-Sissi toppled Islamist president Mohamed Morsi after mass protests against his rule.
Sissi went on to be elected president, winning the support of many Egyptians who praised him for delivering stability, as well as Western powers who view Cairo as a strategic ally.
Egypt denies accusations by human rights groups that its security forces have committed abuses in a clampdown that has killed about 1,000 Islamists and jailed thousands of others. Secular activists have also been arrested.
The report alleged that abuses included rape, sexual assault, rape with objects, electrocution of genitalia, sex-based defamation and blackmail.
Egyptian women shout slogans and hold banners during a protest against sexual harassment in Cairo, Egypt, Saturday, June 14, 2014.
"The scale of sexual violence occurring during arrests and in detention, the similarities in the methods used and the general impunity enjoyed by the perpetrators point to a cynical political strategy aimed at stifling civil society and silencing all opposition,” said Karim Lahidji, FIDH President.
FIDH said the report reveals the involvement of police, National Security intelligence officers and the military in sexual violence, and was based on interviews with victims, lawyers and members of human rights NGOs.
“We were attacked in a raid led by the chief of the Alexandria Criminal Intelligence (Mabahith) ... They made us kneel down with our hands behind our heads," said K, an activist from an Egyptian human rights NGO.
"Then they took the young women to one side and frisked us with our faces towards the wall, sexually harassing us and insulting us. I tried to remove the hand of one of the Central Security soldiers from my trousers, so then they beat me with their weapons until I could no longer resist."
Sissi says Egypt faces an existential threat from the Muslim Brotherhood, which Cairo has branded a terrorist group. The Brotherhood says it is committed to peaceful activism.
FIDH accused Egyptian authorities of taking token measures to combat sexual violence.