Friends and relatives say Hamas killed a grandmother, parents protecting their children, and an entire family during raids

A little after 11pm on Sunday, the Israeli government posted a photograph of a family on one of its social media accounts. There were five people in the selfie: a mother, a father and their three young children, all of them smiling.

“Tamar, Yonatan and their children Shachar, Arbel, Omer,” the caption read. “An entire family wiped out by Hamas terrorists. There are no words. May their memory be a blessing.”

Moments later, the former Israeli prime minister Naftali Bennett reposted the photo.

“An entire family murdered in cold blood,” he wrote. “Look at their happy faces. Their love. All of them murdered by Palestinian terrorists at Nir Oz kibbutz. Just because they’re Jews.”

Although it remains unclear exactly what happened to the Kedem family on their kibbutz, which lies a mile and a half from the border with Gaza, their picture – and the story of their murders – has been widely shared to illustrate the utter pitilessness and ferocity of Hamas’s attack on Israel.

According to friends in Australia, the family rushed to their safe room when the assaults began, from where they sent a WhatsApp message.

“Hi guys, we got into the shelter in our house, we’re all going okay,” the text read.

An hour later, however, Tamar had stopped responding to messages from Yishai and Mor Lacob, her friends in Sydney.