Governments and aid agencies around the world are appealing for immediate help for civilians in Gaza.
The U.S. government expressed support for humanitarian assistance in the Palestinian territory and the State Department said it continues to provide food, medicine and other urgently needed supplies to the people of Gaza through various international agencies and non-governmental organizations.
The Palestinian Authority's foreign minister Riyad al-Malki said Monday Arab governments are working to lift Israel's blockade of Gaza and get supplies to the needy.
Jordan's Queen Rania, along with officials from the U.N. Palestinian Refugee Agency, appealed for a "humanitarian cease-fire" in Gaza. She said civilians, especially children, are not "acceptable collateral damage."
The U.N. High Commissioner for Refugees Antonio Guterres urged other nations -- especially neighboring states -- to respect the right of civilians fleeing war to seek safety in other states.
Egypt is the only nation besides Israel to have a border with Gaza, but it has kept its crossing points mostly closed.
A top U.N. official, Undersecretary-General for Humanitarian Affairs John Holmes, said the U.N. believes at least 25 percent of the casualties in Gaza are civilians.
He called on both Israel and Hamas to refrain from what he called "indiscriminate" and "disproportionate" attacks, and expressed hope that a cease-fire will be reached very quickly.
Gaza residents had already been suffering from severe shortages of basic supplies after Israel tightened its blockade late last year in response to Hamas rocket attacks. The situation has grown worse during the current military campaign, with medical workers saying they are unable to provide adequate care for the estimated 2,000 people wounded in the conflict.
Iranian media say Foreign Minister Manouchehr Mottaki sent a letter to his Egyptian counterpart offering to set up a makeshift hospital in Egypt near the Gaza border to help treat wounded Palestinians.
The aid agency CARE says the Israeli ground offensive has halted the distribution of food and other essential goods, forcing Gaza's population to leave their homes during bombing raids to search for food.