U.N. humanitarian chief John Holmes told reporters Monday that U.N. officials believe as many as 25 percent of the 500 people killed in the fighting are civilians and that Gaza's health system is "increasingly precarious" due to the more than 2,500 injured.
He said Gaza is running low on clean water, power, food, medicine and other supplies since Israel began launching a heavy attack on the militant Islamic group Hamas that controls Gaza's government, first with airstrikes and then with troops and tanks.
Israeli leaders have maintained consistently there is no humanitarian crisis for the Palestinians living in the densely populated territory, and that they have been keeping the border crossings open and are delivering vital supplies.
"This is, in our view, a humanitarian crisis," Holmes countered. "It's very hard for me to see any other way you could describe it, given the conditions in which the population are living."
Holmes said it's "a fair presumption" that most of the civilians killed were women and children.