GAZA Israeli Defense Minister Ehud Barak apologized to U.N. Secretary-General Ban Ki-moon Thursday after Israeli forces shelled the main U.N. aid compound in the city of Gaza, Ban told reporters.
The United Nations Relief and Works Agency (UNRWA) said its compound, where up to 700 Palestinians were being sheltered, was hit twice by fire and three staff members were injured.
Ban, visiting Israel as part of a diplomatic drive for a ceasefire in Gaza, said he had protested strongly to Barak, who apologized and told him it was a "grave mistake."
"I conveyed my strong protest and outrage to the defense minister and the foreign minister and demanded a full explanation," Ban said.
"The defense minister said to me it was a grave mistake and he took it very seriously. He assured me that extra attention will be paid to U.N. facilities and staff and this will not be repeated."
UNRWA spokesman Christopher Gunness said after the shelling of the compound that the agency had put a hold on vehicle movements, but was not suspending aid operations.
Fighting intensified as Israeli forces pushed deeper into Gaza city Thursday and unleashed their heaviest shelling of its crowded neighborhoods in three weeks of war, stepping up pressure on Hamas as the Islamist group weighed a truce.
An explosion blasted a tower block that houses the offices of Reuters and several other media organizations, wounding a journalist for the Abu Dhabi television channel.
At least 15 Palestinians were killed in the fighting and dozens of terrified residents were seen fleeing on foot while thousands more huddled in homes that provided precarious shelter.
The Palestinian death toll from the air-and-ground offensive has risen to at least 1,055, according to the Hamas-run Health Ministry in Gaza.
A Palestinian rights group said 670 of the dead were civilians. Thirteen Israelis have been killed -- 10 soldiers, and three civilians hit by Hamas rocket fire.
Ban said the death toll had reached "an unbearable point."
(Reporting by Louis Charbonneau; writing by Douglas Hamilton; editing by Mark Trevelyan)