As US envoy has arrived in Tel Aviv for de-escalation talks as unrest between Israel and the Palestinians continues.
An Israeli air strike on a refugee camp in the Gaza Strip killed 10 people on Saturday, while a Palestinian rocket killed a man in Israel.
This week’s violence in Gaza and Israel is the worst since 2014.
US President Joe Biden made diplomatic phone calls to Israeli Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas on Saturday.
The international community has urged both sides to end the escalation.
At least 139 people have been killed in Gaza and nine in Israel since this fighting began on Monday. Israel says dozens of militants are among the dead in Gaza, while Palestinian health officials say nearly half are women and children.
The flare-up of violence over the last six days came after weeks of spiralling Israeli-Palestinian tension in East Jerusalem, which culminated in clashes at a holy site revered by both Muslims and Jews.
Hamas began firing rockets after warning Israel to withdraw from the site, triggering retaliatory air strikes.
Thirteen people died in the Gaza Strip on Saturday, with 10 killed by an Israeli air strike at a refugee camp west of Gaza City, Palestinian health officials said.
A five-month-old baby is said to be the only survivor of that strike, found trapped in the rubble next to his dead mother. A number of people were also reported missing.
Saturday also saw an Israeli air strike destroy a tower block in Gaza housing media organisations. No-one is known to have died in this attack.
Israeli officials reported about 200 rocket launches from Gaza overnight, with homes hit in the southern cities of Ashdod, Beersheba and Sderot.
About 2,300 rockets have been fired from Gaza at Israel since Monday, with about 1,000 intercepted by missile defences and 380 falling short and dropping into Gaza itself, Israel’s military says.
On Saturday afternoon, an Israeli air strike destroyed a high-rise building housing media organisations, including The Associated Press and Al-Jazeera, plus a number of offices and apartments.
Mr Amr’s arrival comes ahead of a UN Security Council meeting on Sunday. The US embassy in Israel said the aim of his trip was to “reinforce the need to work toward a sustainable calm.