Gaza Strip since Israel began its bombardment against Hamas, the UN said on Sunday, warning of dire conditions on the ground.
Israel declared war on the Islamist group last Sunday, a day after waves of its fighters broke through the heavily fortified border and shot, stabbed and burned to death more than 1,400 people, most of them civilians.
The relentless bombing since against those who masterminded the attack have flattened neighbourhoods and left at least 2,670 people dead in the Gaza Strip, the majority ordinary Palestinians.
But as Israel seeks to avenge the worst attack in its history, the Arab League and African Union warned the invasion could lead to «a genocide of unprecedented proportions».
UN Secretary-General Antonio Guterres called on Hamas to release all hostages and for Israel to allow humanitarian aid into Gaza, warning that the region was «on the verge of the abyss».
Israel also faced a grave warning about the wider security implications of putting boots on the ground in the densely populated enclave.
«No one can guarantee the control of the situation and the non-expansion of the conflicts» if Israel sends its soldiers into Gaza, said Iran's foreign minister Hossein Amir-Abdollahian.
«Those who are interested in preventing the scope of war and crisis from expanding need to prevent the current barbaric attacks… against citizens and civilians in Gaza,» he added.
Iran is Israel's number one enemy and as well as funding Hamas also backs Hezbollah in Lebanon to the north, where cross-border fire has intensified in the last week, prompting Israel to shut the area to civilians.
Escalation risk
Defence Minister Yoav Gallant said Israel had «no interest in a war in the north, we don't want to escalate