The State Department said Sunday that the United States is "appalled" by the "disgraceful" Israeli missile attack on a United Nations school in Gaza that was sheltering roughly 3,000 people displaced by the recent fighting.
The attack Sunday purportedly killed 10 Palestinian residents, increasing the death toll to at least 1,800 in the 27-day fight between Israel and the Palestinian-backed Islamic militant group Hamas. Sixty Israelis also have been killed in the violence.
"The coordinates of the school, like all UN facilities in Gaza, have been repeatedly communicated to the Israel Defense Forces," State Department spokeswoman Jen Psaki said in a statement.
"We once again stress that Israel must do more to meet its own standards and avoid civilian casualties," Psaki added.
The conflict started with the killings in June of three Israel teens, then the apparent revenge killing of an Arab Palestinian youth. Hamas responded to the teen killing by firing rockets into Israel, and Israel has responded with land, sea and air attacks.
The U.S. condemnation follows one by U.N. Secretary-General Ban Ki-moon, who depicted the shelling near the Rafah school as both "a moral outrage and a criminal act."
Earlier, a senior Palestinian diplomat expressed outrage over killings and bloodshed on both sides in Gaza and called for negotiations to end the savage fighting that has gone on for nearly a month.
"What we need now is to stop this fighting, to address the tragic humanitarian situation in the Gaza Strip," Riyad Mansour, the Palestinian ambassador to the U.N., said on NBC's "Meet the Press," adding "these things need to be stopped."
He said that putting the people of Gaza "in a continuous situation of confrontation and fighting" will only lead to more violence, saying "This is an excellent atmosphere for radicalism."
"But if you give them (Palestinians) hope, you open the borders, you let them go to school, let them look for good jobs, let them look for moderation. And we will succeed in allowing all those who want to have peace...to have the upper hand."
Pierre Krahenbuhl, head of the U.N. agency for Palestinian refugees, called the shelling a clear violation of international law. "These are premises that are protected, the sanctity of which has to be respected by all parties," he said Sunday on CBS' "Face the Nation."
The Associated Press contributed to this report.