The United Nations human rights office has said it was appalled by heavy Israeli strikes on northern Gaza where it said tens of thousands of civilians are trapped without food or supplies, AFP reports.

“In the shadow of the escalation of hostilities across the Middle East, the Israeli military appears to be cutting off North Gaza completely from the rest of the Gaza Strip and conducting hostilities with absolute disregard for the lives and security of Palestinian civilians,” the rights office said.

It added in a statement that it had received reports that Israeli forces had erected sand mounds at a key juncture, effectively “sealing off North Gaza” and firing on those attempting to flee.