An Israeli woman found out her grandmother was killed when Hamas posted a video of her body covered in blood on Facebook

• A woman found out her grandma had been killed by Hamas militants after seeing a video on Facebook.
• The video showed the grandmother lying on the floor, covered in blood, she said.

An Israeli woman found out her grandmother had been killed by Hamas militants when she saw a graphic video on her Facebook page.

Mor Bayder, appearing on Israel's Channel 13, said the video showed her grandmother "lying there" with the floor covered in blood.

"I saw that worst thing you could possibly imagine," she said in Hebrew, adding: "My grandmother, in her house, being murdered in a video."

Bayder said she believed a militant took her grandmother's cell phone, filmed with it, and uploaded the footage to her private Facebook page.

"That's how we found out, how we learned about it," Bayder said.

Her cousin, Yoav Shimoni, appearing on CNN, corroborated the harrowing story.

"My sister commented on our group chat that there is a weird video on my grandma's Facebook," he said. "Then, that is when we all discovered it."

Shimoni said the family believes Hamas militants broke into his grandmother's home after breaching the fence from Gaza, which is less than a mile away from the kibbutz she lived on — Kibbutz Nir Oz.

"I assume she was the first point of contact where the terrorists infiltrated," he said.

In a Facebook post, Bayder described the "brutal murder" as her worst nightmare.

"Those who know me know what she is to me and what a connection we had," she wrote.

Nir Oz is one of the communities near the Gaza border that was targeted in a series of surprise attacks by Hamas on Saturday.

Several people from the kibbutz are missing, including a 74-year-old grandmother.

Israeli officials say Hamas fighters have captured more than 100 hostages, who they believe were taken into Gaza as captives.