Israel said it had largely secured the Gaza border and was evacuating nearby towns where the bodies of 1,500 Hamas militants had been recovered by Tuesday after days of gruelling battles outside the Palestinian enclave.

Prime Minister Benjamin Netanyahu has warned Israel’s military campaign following Saturday’s surprise onslaught was only the start of a sustained war to destroy Hamas and “change the Middle East”.

Fears of a regional conflagration have surged amid expectations of a looming Israeli ground incursion into Gaza, the crowded enclave from where Hamas launched its land, air and sea attack on the Jewish Sabbath.

The death toll in Israel has surged above 900 from the worst attack in the country’s 75-year history, while Gaza officials have reported 687 people killed so far.

Hamas gunmen massacred more than 100 people in the kibbutz of Beeri alone, said Moti Bukjin, a volunteer with the charity Zaka that recovers bodies in accordance with Jewish law.