Simona Steinbrecher holds up two images of her daughter, Doron. One shows a young woman with twinkling eyes and a big smile. The other, from a video distributed by Hamas 107 days into the war, shows an emaciated, pale woman, with an almost lifeless gaze.

Doron, a 30-year-old veterinary nurse, managed to telephone her mother Simona moments before she was abducted to Gaza from her home in Kibbutz Kfar Aza, one of the communities worst hit in Hamas' Oct 7 attack on southern Israel.

In the brief call, Doron said that gunmen were heading to her room.

"It's every mother's worst nightmare," Steinbrecher said.

"It was awful. I'm close by but I can't go to her because the entire area is sprawling with terrorists - I know she is being kidnapped and I can't help her," she said.

Doron is one of 134 hostages still held in Gaza, which has been under Israeli land, sea and air bombardment since Oct 7, in an offensive that has killed more than 30,000 people and laid much of the enclave to waste.

Steinbrecher's nightmare was made worse in late November, when some hostages released in a swap deal reported abuse in captivity. "Doron is a young woman and the fear is of sexual violence, rape, even pregnancy," she said.

At least three released female hostages have spoken publicly, including one in an interview with Reuters, about incidents of sexual abuse against fellow captives.

Hamas has repeatedly denied allegations of sexual violence.

A report by a UN team of experts released on Monday said they found "clear and convincing information" that some hostages were subjected to sexual violence and that such violence may be ongoing.

'HELL ON EARTH'

The UN report came four days before Friday's International Women's Day, which has taken on extra significance in Israel this year with the fate of abducted women unknown.

"My daughter is inside Gaza," said Meirav Leshem Gonen, whose 23-year-old daughter Romi is still being held incommunicado. "This is hell on earth - what Women's Day? What exactly does this Women's Day say if she's so unprotected?"

Romi was kidnapped from the Nova open-air music festival, where 364 people were shot, bludgeoned or burned to death. Romi managed to tell her mother on the phone that she had been wounded by gunfire before contact was lost.

In the five months since, Leshem Gonen, like Steinbrecher, draws her strength from the fight to bring her daughter home. Both mothers are active campaigners - speaking at parliament and at protest rallies, giving interviews abroad and meeting Israeli and foreign leaders.

"This is a different universe for us. Nothing is the same," said Leshem Gonen. Emotions like anger, sadness and fear, she said, have been set aside because they simply don't help her campaign for her daughter's freedom, she said.

"When you decide that you fight for life, all other things don't matter," said Leshem Gonen.