UPDATE (October 5, 2011):
A woman claiming to be Zainab appeared on Syrian state television Tuesday. She showed her identification card and told her interviewer that she had been staying with a relative, unbeknownst to her family. She says she left home because she was being abused by her brothers.
Amnesty International, which broke the story, said Wednesday it was looking into the case with the help of its sources in Syria. The organisation wrote in a statement: “If the body was not that of Zainab al-Hosni, then clearly the Syrian authorities need to disclose whose it was, the cause and circumstances of the death, and why Zainab al-Hosni's family were informed that she was the victim.”
According to both Human Rights Watch and Amnesty International, Zainab's parents now live in a neighboring country. They organisations said in a joint statement that the mother, whom they spoke to, recognized her daughter on Syrian state television.
Zainab's mysterious reappearance has raised many questions from Syrian activists: If the young woman ran away, why did she take weeks to show herself following the news of her gruesome death, which spread around the world? Is the fact that one of her brothers was a well-known activist, who was arrested and died in prison after her disappearance, only a coincidence? And to whom belongs the body  buried in Zainab's tomb?
Zainab al-Hosni, an 18-year-old woman, was found beheaded, dismembered and skinned after being detained by alleged Syrian security forces, according to human rights groups. She is believed to be the first woman to have died in custody. Our Observers in the central Syrian city of Homs, where Zainab was from, tell us how this gruesome case has shocked women and enflamed protesters.
According to Amnesty International, which spoke with sources privy to the case, the young woman was abducted in July by men suspected as members of the Syrian security forces to pressure one of her brothers, a prominent activist, to turn himself in. Mohammed al-Hosni was later arrested himself and died in custody, said the group. When his parents were asked to pick up his body at the morgue two weeks ago, they were shown their daughter’s heavily mutilated body as well. They buried her on September 17.
Zainab al-Hosni's funeral. Video posted on YouTube by SHANSNN.
Since then, a video purported to be that of Zainab’s corpse has circulated online, infuriating anti-regime protesters, who have nicknamed her “the flower of Syria.” According to Amnesty International, this is the same video they were given by their sources close to the case. (Due to the graphic nature of these images, FRANCE 24 has decided not to publish them.) A man who presents himself as another one of Zainab's brothers released a video statement, in which he details the circumstances of his siblings’ deaths.
A man who presents himself as Zainab al-Hosni's brother gives his version of events. Video posted on YouTube by MrAA991.
According to Amnesty International, a total of 103 people have been killed in custody since the beginning of the uprising in March.

“Most families won’t allow girls to leave their homes anymore”

Mona (not her real name) is one of our Observers in Homs. [FRANCE 24 spoke to her shortly after Amnesty International said Zainab had died].
I first heard about Zainab’s murder last week. At first, people thought it might be just a rumour, but then we saw images of the funeral and photographs of her body. I was in shock. It took me an hour to recover. It’s inhuman, what they did to her. We knew girls were being raped, but we couldn’t imagine security forces could do something that cruel, that they could damage a body to that degree.
Her death hasn’t stopped protesters, however. It has just made the men angrier. But for girls, it is really depressing.
We have seen images of bodies without arms before. But they were men, and this time it’s a girl. Most families won’t allow girls to leave their homes anymore for fear they will be abducted. Me, I have stayed at home for four months now. I no longer go to university. I only go out by car, never by foot. But now, I am preparing myself for the worst – I may stop going out at all.
More and more girls are disappearing. We hear so many stories about girls being kidnapped and raped - some are kept in custody, others are sent back to their families.
They terrorise women to force their brothers or fathers to stop protesting, or even to punish an entire neighbourhood. They know that hurting a girl will hurt her whole neighbourhood. It’s a game they play to scare us.”

“Girls are beginning to disappear daily”

Freesyria (not his real name) is an activist who lives in Homs.
Everyone is very sad here. Women are crying for Zainab. She was an innocent young girl; her only guilt was being the sister of someone the security forces wanted to get. They are targeting women because they want to anger us and start a war between us.
People in Homs are afraid. Girls are beginning to disappear daily. No one knows where they are. We have asked all girls to go out accompanied, and not to go out after dark at all. We have people watching out for their safety during daylight hours downtown. In the past couple of months people in Homs have bought many guns; if the secret police attack, we want to be able to defend the women. Despite this fear, we will continue to protest.”