U.N. Secretary General Ban Ki-moon on Jan. 20 inspected the devastation wrought by Israel's onslaught in Gaza, leading a moment of silence at the smoldering U.N. headquarters in the Israeli territory, as the territory's militant Hamas rulers, triumphant at having survived, held victory rallies amid the ruins.

A Palestinian girl cries after her uncle, missing for 20 days, was found dead under the rubble of a house in the Gaza Strip on Jan. 19. AP PHOTO

Israel and Hamas both ceased fire Jan. 18, after an offensive that claimed the lives of at least 1,259 Palestinians, more than half of them civilians, according to the United Nations, Gaza health officials and rights groups. Thirteen Israelis died, including four soldiers killed inadvertently by friendly fire.

The last of Israel's ground troops were expected to pull out of Gaza on Jan. 20, if the quiet holds, Israeli defense officials said.

Ban, appearing stern and saddened at the U.N. ceremony, demanded a full investigation into strikes on U.N. facilities. He asked the crowd to honor victims of the offensive, who included nearly 40 Palestinians who had sought refuge at a U.N. school shelled by Israel.

"It has been especially troubling and heartbreaking for me as secretary general that I couldn't end this faster," he said. He warned that the truce is fragile, and called on Israel and Hamas to "exercise maximum restraint and nurture the cease-fire."

Ban did not meet officials from Hamas, whose government is not internationally recognized.

Israel launched the offensive Dec. 27 in an effort to halt years of militant rocket fire on its southern communities and arms smuggling into Gaza.