UN chief Antonio Guterres on Thursday slammed Israel and Palestinian for the "unacceptable" crossfire between them, as he told the UN General Assembly that "the fighting must stop immediately".
"I am deeply shocked by the continued air and artillery bombardment by the Israeli Defence Forces in Gaza," Secretary-General Guterres said of the salvos that have killed more than 200 Palestinians, including 60 children.
He added that the "indiscriminate firing of rockets by Hamas and other groups" towards population centres in Israel — which have left 12 dead, including two children — was "also unacceptable."
"If there is a hell on earth, it is the lives of children in Gaza," he said.
The General Assembly meeting was requested by Niger and Algeria, respectively, the current chairs of the Organisation of Islamic Cooperation and the Arab Group at the United Nations.
"It is imperative that we achieve de-escalation, to prevent an uncontainable crossborder security and humanitarian crisis," Guterres said, calling for the "resumption of negotiations" pursuing "a two-state solution on the basis of the 1967 lines."
On Wednesday, the 10th day of deadly violence between Israel and armed Palestinian groups in Gaza, a spokesperson for the Secretary-General said Guterres had had contact with Palestinians and officials in the Middle East, but not yet with Israeli Prime Minister Benjamin Netanyahu.
Denouncing airstrike damage to "several hospitals," the UN chief also called the levelling of media offices as well as the killing of a journalist in Gaza "extremely concerning."
"I am deeply distressed by damage to United Nations facilities in Gaza," he said. "United Nations premises are inviolable, including during armed conflict. Humanitarian installations must be respected and protected."
He said an appeal for humanitarian aid donations would launch "as soon as possible," specifying that the UN would release $14 million from the Humanitarian Fund for the Occupied Palestinian Territories.
"There is no justification, including counterterrorism or self-defence, for the abdication by the parties to the conflict of their obligations under international humanitarian law," Guterres said.
"I am also deeply concerned by the continuation of violent clashes between Israeli security forces and Palestinians groups across the occupied West Bank, including East Jerusalem, where several Palestinian families are under the threat of eviction."
A years-long bid by Israeli settlers to take over Palestinian homes is among the origins of the escalation in violence between Israel and Hamas that began May 10.
