meanwhile, the legal conundrum

John Ging of Unrwa has raised the question of whether Israel's government should be investigated for committing possible war crimes against Palestinians.

"For all those innocent people who have been killed in this conflict, were they war crimes? International law obliges is to get an answer to that question," he said.

Mr Ban has been more cautious, saying it is not for him to determine whether a war crimes investigation should take place. However, he has stressed the importance of accountability, where necessary.

In reality, a war crimes investigation by the International Criminal Court (ICC) is unlikely. The court's prosecutor and pre-trial chamber can only instigate their own proceedings against a state that belongs to the court. Israel is not a formal member.

The UN Security Council has been known to refer cases against non-members to the ICC, but the US, staunch ally of Israel, could well block such a move. A state party to the court can ask for a referral to the ICC, but there is no Palestinian state.

[source: the BBC's UN chief's impact on Gaza truce]