Israel followed through on its vow to intensify attacks, striking targets across Gaza as well as a mosque in the occupied West Bank and two airports in Syria over the weekend.
The war with Hamas is threatening to spiral into a broader conflict, with the US warning Iran that "if this war grows, it is coming to your backyard".
Meanwhile Egyptian border guards were injured after an Israeli tank "misfired" in the Kerem Shalom area.
Along the border at the Rafah crossing, an aid convoy of 17 trucks prepared to enter Gaza on Sunday after 20 were allowed through on Saturday.
Agencies started distributing the first supplies on Sunday - but are still warning of a humanitarian disaster as food, water and fuel run dangerously low.
Israel is widely expected to carry out a ground invasion of Gaza in response to a surprise attack by Hamas militants on 7 October.
The Israeli military has said there are 212 people being held hostage in Gaza ahead of the expected offensive.
That is higher than previously thought, when 199 and later 203 were given as figures for the number of captives.
US and Israel sound warning to Hezbollah
US Senator Lindsey Graham told a press conference in Tel Aviv it was "laughable" to think the situation "happened without Iranian involvement".
He said if the war expands, "there won't be two fronts there will be three".
"If there is an effort to unleash Hezbollah on the Jewish state to destroy it, my attention will be to Tehran," Mr Graham said.
Along Israel's northern border with Lebanon, the Iran-backed Hezbollah group has clashed with Israeli forces in the deadliest escalation of frontier violence since an Israel-Hezbollah war in 2006.
With violence increasing, Israel added 14 more communities in the north close to Lebanon and Syria they would need to evacuate.
Israeli Prime Minister Benjamin Netanyahu warned Hezbollah on Sunday against opening a second war front with Israel.
He said that doing so would bring Israeli counter-strikes of "unimaginable" magnitude that would wreak "devastation" on Lebanon.
Two dead in mosque strike
Israel has said it carried out its airstrike on the Al Ansar mosque in the Jenin refugee camp in the West Bank overnight because it was used as a "command centre to plan and execute terrorist attacks against civilians".
The Palestinian health ministry said two people who are yet to be identified were killed in the strike on the mosque.
The health ministry later said Israeli forces killed a total of eight people in the West Bank on Sunday.
The fatalities mean 93 Palestinians have died there since the conflict began two weeks ago, according to the Palestinian health ministry.
It came as more than 50 Palestinians were killed in Israeli airstrikes on Gaza overnight, medical sources in the territory said.
Two people were also killed after Israel struck Damascus International Airport and Aleppo International Airport in Syria, according to the country's general directorate of meteorology.
The Palestinian health ministry said on Sunday that more than 4,741 Palestinians had been killed and almost 16,000 wounded in Israeli strikes on Gaza since the conflict began.
Official Israeli sources say 1,400 people have died in Israel since the Hamas incursion.
Israel has been conducting airstrikes on Gaza, saying it is trying to destroy the militant group.
A different kind of conflict is emerging on the West Bank
What Hamas's release of US hostages could mean for Israel's expected invasion
Gaza-Egypt crossing opened as lifesaving aid trucks allowed to enter
Many of those killed in the West Bank die in clashes with Israeli forces rather than airstrikes.
However, the latest strike on the West Bank was the second in recent days - with five children among 13 people who were killed after Israeli forces raided and carried out an airstrike on a Palestinian refugee camp on Thursday.
The raid was conducted on the Nur Shams camp, adjacent to the city of Tulkarm, near the territory's border with Israel.
Ground invasion expected
Tanks and tens of thousands of Israeli troops have massed at the border with Gaza as a ground invasion is expected.
However, the military acknowledges there are still hundreds of thousands of Palestinian civilians in northern Gaza, despite a sweeping evacuation order, which would complicate any ground attack.
Increase in illnesses due to lack of clean water
Hospitals packed with patients and displaced people are running low on medical supplies and fuel for generators due to the siege, forcing doctors to perform surgeries with sewing needles, using kitchen vinegar as disinfectant, and without anaesthesia.
Palestinians sheltering in UN-run schools and tent camps are running low on food and drinking dirty water.
The territory's sole power plant shut down more than a week ago, causing a territory-wide blackout and crippling water and sanitation systems.
The UN humanitarian agency said cases of chicken pox, scabies and diarrhoea are increasing because of the lack of clean water.