Israel's prime minister says the Israeli military fired artillery shells at a U.N. compound in Gaza after militants opened fire from the location.
Ehud Olmert says Israeli forces "were attacked from there and the response was harsh."
U.N. chief Ban Ki-moon expressed "outrage" over the Israeli shelling of the compound Thursday.
At a meeting between the two, Olmert called the shelling a "sad incident" but said militants were responsible. The U.N. denies the Israeli allegation.