A British-Israeli woman has told the BBC she is "worried sick" for the health of her diabetic mother and brother who are believed to among the hostages held by Hamas in Gaza.

Ayelet Svatitzky's mother Channah Peri, 79, and brother Nadav Popplewell, 51, were taken by Hamas when their kibbutz in southern Israel was attacked on 7 October.

Her other brother Roi, 54, was killed.

She called on the UK government to do "everything in its power" to secure their release.

On the day of the attack, Ms Svatitzky said she received two pictures, sent by the attackers from her mother's phone, showing the pair sitting in her mother's living room. Underneath was written "Hamas" in English.

Hours later, a third picture was posted on her mother's Facebook showing them with an armed Hamas gunman in the corner.

"That was the last I heard of them," Ms Svatitzky said.

"My mom is 79, she has diabetes. She uses insulin daily. My brother Nadav is also diabetic. So he takes pills for that condition, so the medication issue is really troubling and worrying."

Ms Svatitzky says she does not know how long she can survive without insulin, or her brother without medication.

"We haven't been able to get the Red Cross over to provide medication and provide us with any kind of and updates, proof of life, or what state they're in."

Ms Svatitzky said has been unable to grieve for her brother, who was found shot dead at the back of his home after the attack at Kibbutz Nirim.

"His body hasn't been officially identified. I haven't buried him yet. I've lost my brother but I have to do everything in my power to bring my mom and Nadav home.

"I want the British government to do everything in their power... to bring those people home."

She added: "Taking the elderly people and young children, it's a war crime as far as I'm concerned. These are innocent people, they haven't harmed anyone."

Ms Svatitzky and her brothers are all British citizens. The family originally came from Wakefield, West Yorkshire.

Immigration Minister Robert Jenrick said on Sunday the UK was "working intensively with all our partners across the region to secure the release of British nationals" held hostage by Hamas.

Ofri Bibas Levy's said it was her "worst nightmare" when she discovered her family members had been taken hostage from their home in Nir Oz.

She has not heard from her brother, Yarden, 34, his wife, Shiri, and their two children, four-year-old Ariel, and nine-month-old Kfir.

"I heard what the Hamas was doing that day. They were torturing people, burning them alive, killing babies, raping women and I couldn't imagine what they were going through.

"I don't know what happened inside the house, what the little babies saw in their house."

She does not know if the family are still together and she is worried if the children's basic needs are being met.

"What are they eating? Are they keeping warm? How are they spending their days? Are they locked somewhere? Do they have sunlight? Are they in a dark place?

"Did they see any horrible things that the child shouldn't see?"

She said nine-month-old Kfir had just started crawling and eating formula food before they were taken hostage.

For two weeks her family have asked the international community for support but now "I just want action", she said.

She said she wanted the government to put "pressure for any kind of humanitarian organisation to go inside and check on them and to release them".

"They are civilians and are not supposed to be there. The longer they are there the harder it's going to be to recover them and the less chance they're going to come out alive."

Asked if she still has hope, she said: "I have to."