UK Chief Rabbi Sir Ephraim Mirvis has said his cousin and cousin's wife "spent 15 terrifying minutes hiding under a doughnut stand" as gunmen opened fire during the Bondi Beach attack.
"People to their right and left were being shot dead," the rabbi said.
Fifteen people have been killed – including a 10-year-old girl – in an attack by the two gunmen targeting a Jewish Hanukkah celebration on the beach in Sydney.
Rabbi Mirvis said one of the key messages of Hanukkah is that Jews around the world declare "we belong, and we will not hide who we are", but "that declaration was met with murderous hatred" at Sunday's mass shooting.
The causes of "toxic antisemitism" must be addressed, he said.
