The U.N. and Red Cross criticized Israel for imperiling relief workers and restricting the delivery of aid throughout the Gaza Strip.
The international Red Cross also complained that Israel was imposing "unacceptable" delays on its workers and said it was restricting its movement inside Gaza during Israel's ongoing offensive against Hamas.
Just two days after a tank shell killed about 40 Palestinians, mostly civilians, taking refugee in a UN school in the Jabaliya refugee camp, a spokesman for the UN in Gaza accused the Israeli army of ignoring efforts to coordinate movement amid the fighting.
The Red Cross complained that Israel is hindering access to civilians.
Because the UN is one of the biggest providers of food and medical relief, halting shipments to Gaza will accelerate the worsening conditions in the besieged coastal enclave of 1.5 million Palestinians. Israel is facing growing criticism due to the poor humanitarian conditions inside Gaza, and a burgeoning crisis would likely lead to more international pressure for a withdrawal of its forces.