Sara Atef was wearing her school uniform on the day she was arrested by riot police.
The 16-year-old had become a regular sight at anti-government rallies organized by Muslim Brotherhood-affiliated groups in her hometown of 6 October city, a sprawling satellite development an hour's drive from central Cairo.
Sara, who says her first experience of protesting was in Tahrir Square in 2011, had already had a few brushes with the security forces.
"I was at a protest a few days earlier, and the police came and dispersed us, but I managed to run away," she said.
On December 24, she was not so lucky. According to her, the police fired teargas and birdshot at a large crowd of protesters who had gathered to demonstrate against last summer's ousting of President Mohamed Morsi.
As security forces closed in on Sara and her friend Ola, the pair ran into a nearby supermarket. "We were trying to escape out of the back door, but as we got outside we saw the way was blocked by police vans," she said. "I tried to call for help but the police - and the thugs working with them - formed a big circle around us to stop anyone taking pictures."
The girls were handcuffed together and taken into detention. They were subsequently charged with a number of offences, including thuggery, using violence, and being members of a terrorist organization - referring to the Brotherhood. Sara, who says she supported Morsi but is not a Brotherhood member, spent a month in detention, and is now at home waiting for her case to go to trial. Her 15-year-old friend, Ola, has yet to be released.
Children's rights advocates say that, while the arrest of minors at protests is not a new phenomenon in Egypt, their treatment once detained is a major cause for concern.
According to Maha Maamoun, a human rights activist who works on children's rights issues, large numbers of minors are taken into custody when security forces round up and arrest suspects at protests and clashes.
"Around 10 to 30 percent of the people they detain will be children," she said. "In some ways, they're just easier to catch."
Once detained, Egyptian laws - and the newly passed constitution - dictate that minors should be held in separate facilities to adults.
"In many cases this is not done," said Maamoun. "It depends on the place of detention, but we hear many cases of the law not being upheld - minors being held with adults who are accused of crimes, or not being allowed visits from their parents or their lawyers."
Sara was held in a windowless cell at a police station - alongside adult women charged with criminal offences - during her month-long detention, but said she was "lucky" to be treated well by her cellmates. "One of the women, who was detained for theft, helped me get medicine from outside when I needed it," she recalled.
Egyptian law also specifies that minors such as Sara should, where appropriate, be processed by juvenile specialists rather than by adult courts.
"According to amendments made to the Children's Law in 2008, children have to go in front of a juveniles' prosecutor, and appear in front of a juvenile court - except in cases where they are charged alongside adults," said a lawyer from the Egyptian Initiative for Personal Rights, who asked not to be named for security reasons.
The lawyer, who works with detainees in the Cairo area, said that in most of the cases he was dealing with, children had not been referred to specialist courts.
"We have one ongoing case in which 228 defendants, a significant number of them minors, were arrested in Abdeen [in central Cairo] on the anniversary of the January 25 revolution - and are being charged with murder," he said.
"In this case, the children are being charged alongside adults."
The boys in the Abdeen case, according to the lawyer, are being held inside a camp belonging to Egypt's notorious riot police, the Central Security Forces. Children's rights advocates warn of serious violations associated with the detention of minors at these camps, and, in a statement published on 30 January, the Egyptian Coalition for Children's Rights demanded an immediate investigation into allegations of torture at the site.
"It used to be very rare to detain minors in CSF camps. They were mostly kept in police stations. But after Morsi's ousting, we are seeing it happening more frequently, usually citing 'security reasons'," said the lawyer.
"We don't have any access to the detainees that are held in these places, and when the prosecution starts their investigations, lawyers are not present, which is completely illegal," he added.
Maamoun agrees that detention of children at CSF camps is a major violation of the law. But she stresses that physical abuse is widespread in detention - even outside these notorious camps.
"Many children who get arrested are subject to torture at some point by the police, or by soldiers. The norm is that they are beaten in the police vehicles, or when they first arrive in the detention facility," she said.
In one case on January 25, two 15-year-old boys were "quite badly beaten" at a police station in central Cairo, said Maamoun.
According to the activist, other forms of torture have also been reported.
"I have heard of at least one case [in recent months] of a child being subjected to electric shocks while in detention," she said.
In some cases, minors find themselves on the wrong side of the law even without participating in unauthorized protests. Khalid Bakara, a 15-year-old from the coastal province of Kafr El-Sheikh, was caught in November by a school teacher with a ruler bearing the Rabaa symbol, an emblem of the pro-Morsi cause, and arrested the same day.
Bakara's lawyer, Amr Abdel-Maksoud, told Al Jazeera that Khalid had been released on bail after 30 days' detention, most of which was spent at an adult facility within a military prison.
He is currently charged with "possession of a ruler that has a symbol that shows violence and offence towards the armed forces", according to Abdel-Maksoud, who added that prosecutors have issued arrests warrants for Khaled's father and one of his teachers, both of whom have gone into hiding.
"It is clearly a politicized case. He should never have been arrested and detained on this charge - it is a matter for the school administration only," said Abdel-Maksoud.
It is not just the ongoing arrests of minors that have sparked concern among children's rights advocates.
Last summer, pictures of young children at a pro-Morsi protest camp holding signs and wearing white shrouds associated with martyrdom caused widespread outrage. The state-run National Council for Childhood and Motherhood decried "the exploitation of children", while Mervat Tellawy, a state official who heads up the National Council for Women, said that it would lead to "the creation of a new generation of terrorists".
Similar issues surfaced last month as Egyptians went to the polls to vote on a new constitution. A number of pictures and videos circulating on social media showed groups of children, reportedly orphans from a state-run facility, holding pictures of armed forces chief Abdel-Fattah El-Sisi.
"Both sides exploit children," said the EIPR lawyer. "We see pictures now of children at protests with military boots on their heads, supporting Sisi. But children should be kept away from all protests and demonstrations. They are dangerous places."
Maamoun argues that such cases expose a wider societal failure to protect children from serious violations.
"According to the Children's Law, it is illegal to expose minors to danger in this way, or to use them for political purposes. It's against the law, whether it's done by the state or by the parents, and these people should be being charged according to the law," she said.
"The situation has been getting worse and worse for children since 2011. It's not just the state - the whole community is failing children. Until we recognize that children are vulnerable and need to be better protected, we will continue to destroy Egypt's future."
Children play on a sandbar in the Nile near downtown, Cairo, Egypt, Wednesday, Feb. 12, 2014.