During a trip to the rocket-scarred Israeli town of Sderot, Ban said the projectiles are indiscriminate weapons, and Hamas attacks are violations of basic humanitarian law. However, he also urged Israel to end its crippling blockade of Gaza. He says the embargo will only strengthen Hamas by fueling desperation in impoverished Gaza.
Ban was touring Israel and Gaza on Tuesday in the wake of a deadly Israeli offensive in Gaza. Israel launched the operation to end years of rocket fire on Sderot and other southern towns.
THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.
GAZA CITY, Gaza Strip (AP) - The U.N. chief inspected the devastation wrought by Israel's onslaught in Gaza on Tuesday, leading a moment of silence at the smoldering U.N. headquarters, as the territory's militant Hamas rulers, triumphant at having survived, held victory rallies amid the ruins.
Secretary-General Ban Ki-moon, appearing stern and saddened at a ceremony at the burned out U.N. headquarters in Gaza, demanded an Israeli investigation into strikes on United Nations facilities. Ban asked the crowd to observe a moment of silence for 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 the truce is fragile, and called on Israel and Hamas to "exercise maximum restraint and nurture the cease-fire."
Thousands of Hamas supporters thronged a square outside the remains of the parliament building in Gaza City, which was heavily damaged in an Israeli airstrike at the outset of the war. Two men hoisted a sign in carefully scripted Hebrew reading, "The resistance will be victorious, Israel has been defeated."
Israel and Hamas both ceased fire on Sunday, after an offensive that claimed the lives of some 1,300 Palestinians, according to Gaza health officials, and 13 Israelis. The last of Israel's ground troops were expected to pull out of Gaza on Tuesday if the quiet holds, defense officials said.
Israel mounted an air and ground offensive against Hamas on Dec. 27 in an effort to force Gaza militants to halt their rocket fire on southern Israel and to cripple arms-smuggling operations. The fighting stopped before Israel achieved those aims.
The U.N. chief personally intervened to try to stop the war, and said over the weekend that he was sending a team to assess the humanitarian needs so the United Nations could issue an emergency appeal for funds.
Calling the crisis a "collective political failure," Ban said he would share the findings of his trip to Gaza with world leaders, including incoming President Barack Obama.
The first estimates by independent surveyors said Gaza lost nearly $2 billion in assets, including 4,100 homes, about 1,500 factories and workshops, 20 mosques, 31 security compounds, and 10 water or sewage lines. Shattered glass and mounds of rubble littered city streets.
Ban called the attacks on the U.N. headquarters and two of its schools "outrageous" and demanded a full investigation through proper judiciary systems. He also demanded guarantees it would never happen again.
Israel has said militants used the U.N. buildings as cover to launch attacks, but the military has launched its own investigation.
Homeowners digging through the debris in Gaza City, the territory's largest city, carried off vases, refrigerators, dishes and baby beds, some loading their goods into cars and trucks. Utility crews began planning repairs to electrical and sewage and water systems. A senior technician, Mofid Awad, said 80 percent of the electricity grid in Gaza City was damaged.
Before setting off for Gaza, Ban met with Israeli Prime Minister Ehud Olmert, who told him Hamas could not be allowed to lead the reconstruction process in Gaza and thereby gain some measure of legitimacy, Olmert's office said in a statement.
Ban said his discussions with Olmert focused on withdrawing all Israeli troops from Gaza and how to open Gaza's border crossings.
Ban is the most senior international official to visit Gaza since Hamas militants seized power in June 2007. The Hamas government is not internationally recognized, and Ban was not scheduled to meet with the group, which is regarded by Western powers and Israel as a terrorist organization.
After visiting Gaza, Ban was scheduled to travel to the rocket-scarred Israeli town of Sderot. A false alarm of an incoming rocket in southern Israel earlier in the day set off fears that the shaky truce hadn't even lasted two full days. The military reported that a mortar was fired later, but apparently fell short of Israeli territory.
Palestinians and human rights workers reported that Israeli troops have shot to death two Gaza farmers since the truce took hold, including a 20-year-old man killed in northern Gaza on Tuesday. The military had no comment on that report.
As Ban marshaled a global response to the suffering in Gaza, Hamas was busy planning nine victory rallies across Gaza.
Although Israel scored a decisive battleground victory, Hamas claims its own victory because it managed to withstand the intense Israeli assault and fired hundreds of rockets into the Jewish state throughout the fighting.
In a sign the militant group remained in control in Gaza, Hamas security teams in uniforms patrolled Gaza City.
"With full trust and full confidence I say the Palestinian people and the heroic resistance have won this battle," Mushir al-Masri, a Hamas official, said Monday. "Hamas today is stronger than any time before. ... The loser is the occupation."
Thousands of Hamas supporters turned out to celebrate in the southern Gaza town of Khan Younis, raising their forefingers in the air as a sign of the their loyalty to the militant group, and waving the movement's iconic green flag. Bearded organizers in yellow vests kept the crowd in order and pro-Hamas music blared from loudspeakers.
Around 800 people showed up for a pro-Hamas demonstration in the northern Gazan town of Beit Lahiya, the site of heavy fighting.
"For us, this was a victory," said Mohammed Abu Awad, 24, a university student.
But the owner of a coffee stand located near the Gaza City rally criticized the festivities, given the steep Palestinian death toll.
"We can't talk about real victory because there were thousands of martyrs and we didn't liberate anything," said Jawdat Abu Nahel. "It's no time for a parade."