UN chief Ban Ki-moon demanded Tuesday an independent probe into Israel’s deadly shelling of a school during the Gaza conflict, expressing shock at the devastation during a visit to the Palestinian enclave.

Two days after donor states pledged $5.4 billion (4.3 billion euros) to rebuild Gaza, Ban toured some of the areas worst hit during the July-August war between Israel and the territory’s Hamas rulers. ‘No amount of (UN) Security Council sessions, reports or briefings could have prepared me for what I witnessed today,’ he said after being driven through the ruins of Gaza City’s Shejaiya district and the nearby Jabaliya refugee camp.

The secretary general was speaking at a UN school in Jabaliya, where tank shells slammed into two classrooms on June 30, killing at least 14 people sheltering there. ‘The shelling of the United Nations school is absolutely unacceptable. These actions must be fully and independently investigated,’ he said. Relatives of the dead held up posters showing their loved ones and disabled casualties waited to see Ban.

At Sunday’s conference in Cairo, Ban said ‘the root causes of the recent hostilities’ were ‘a restrictive occupation that has lasted almost half a century, the continued denial of Palestinian rights and the lack of tangible progress in peace negotiations.’ On Tuesday, he urged Israeli and Palestinian leaders to revive peace talks. ‘I’m asking the leaders of both parties... to resume their talks,’ he said. ‘Otherwise it’s a matter of time that the violence will continue.’

Ban said a first shipment of building materials was on its way to Gaza through Israel under an agreement reached last month. ‘I’m very happy to announce that the first truck carrying... construction materials is coming to Gaza today,’ he said. The Israeli army said it had ‘transferred construction materials to the Gaza Strip in order to facilitate rehabilitation projects.’ It said the supplies were ‘expected to include 600 tons of cement, 50 trucks of construction aggregates and 10 trucks of metal.’

Moreover, two days after donors pledged $5.4 billion in aid for Gaza reconstruction, UN Secretary General Ban Ki moon visited the war-ravaged enclave, where he viewed destruction wrought by the recent Israeli military offensive was ‘beyond description’, and also met with the ministers of the National Consensus Government calling on them to focus all efforts on ‘building one Palestine.’

 ‘We stand by you. The international community supports your government’s efforts to assume the security and governance responsibilities in Gaza,’ the UN Chief said in remarks following his meeting with the top officials of the government including its Deputy Prime Minister Ziad Abu, according to teh text of his remarks issued at UN Headquarters in New York.

Ban said that while he was deeply moved by the destruction he had seen in Gaza, there are signs of hope. The Government of National Consensus has brought together Palestinian factions that have ‘too long’ been divided. And the agreement between Israel, the United Nations and the Palestine government has facilitated the arrival today of the first truck bringing in cement and other construction material. ‘This is a great opportunity to unite the West Bank and Gaza under one Palestinian leadership,’ he added.

He also highlighted several important developments that ‘should facilitate your government performing its functions in Gaza’ including the management by the Palestinian Authority of the Gaza crossings, in enabling the flow of materials and restoring trade between the West Bank and Gaza.  The secretary-general’s Gaza visit comes on the heels of a weekend conference held in Cairo in support of the UN-backed plan on reconstruction of the enclave following a 51-day conflict in which entire neighbourhoods were flattened and almost one-third of Gaza’s population was uprooted.

 The violence killed more than 2,100 Palestinians, including more than 500 children, and more than 70 Israelis, according to UN figures. Ban talked with several people who have been deeply affected by the conflict. ‘I just met a man who lost his legs. He lost his brothers and sisters. It is very sad and heart-breaking,’ said the UN chief. He also talked about his visit today to the Jabalia school and meeting the children of Gaza, saying that being born in Gaza should not be a crime.

‘My visit today to the school and to Gaza has reinforced my conviction that there is no time to lose. There can be no peace in the Middle East, no security for Israel, while the crisis in Gaza festers,’ the UN chief said, declaring that the ‘build-destroy, build-destroy cycle must be broken’. ‘The mindless pattern of blockade, rockets and destruction must stop. I repeat here in Gaza: the rockets fired by Hamas and other armed groups must end,’ said Ban.