The death toll from Israel's seven-day air campaign against Gaza militants rose to 177 yesterday, as a UN official said more than a quarter of those killed were children.
In the latest bloodshed, an Israeli missile struck a motorcycle east of the south Gaza city of Khan Yunis, killing 17-year-old Ziyad al-Najjar, emergency services spokesman Ashraf al-Qudra said.
His death came shortly after another strike in the same area, which killed a 37-year-old who was standing with a group of men, Qudra said.
A 60-year-old man was killed in a raid on a house in Deir al-Balah in central Gaza, and two other people died in separate strikes elsewhere in the coastal enclave, he said in a statement.
Earlier, a man and a woman wounded in air strikes on Sunday died of their injuries, Qudra said, raising to seven the number of lives lost yesterday as a result of the air campaign.
So far, more than 1,280 have been wounded.
Also yesterday, the United States warned against any Israeli ground invasion of Gaza, saying it would put even more civilians at risk than are currently in the crossfire of attacks on Hamas.
But the White House stopped short of criticizing Israel over the civilian toll so far in Gaza of the offensive, saying the government had a "right" and "responsibility" to defend their citizens against rocket attacks.
"Nobody wants to see a ground invasion because that would put more civilians at risk," White House spokesman Josh Earnest said during his daily press briefing.
It was the first time that the White House has specifically warned in a public forum against a full Israeli invasion of Gaza, though other US officials, including Secretary of State John Kerry, have previously said Washington would not like to see such a step.
Meanwhile, the Palestinian Hamas movement said it would not end hostilities with Israel without concessions by the Jewish state and that no serious efforts towards a truce had been made.
"Talk of a ceasefire requires real and serious efforts, which we haven't seen so far," Hamas MP Mushir al-Masri told AFP in Gaza City yesterday.
Masri said Hamas would only negotiate on the basis of a set of concessions it wants to see Israel agree to.
Those include the lifting of Israel's eight-year blockade on the Gaza Strip, the opening of the Rafah border crossing with Egypt and the release of Palestinian prisoners Israel has rearrested after freeing them in exchange for kidnapped Israeli soldier Gilad Shalit in 2011.
"Any ceasefire must be based on the conditions we have outlined, nothing less than that will be accepted," Masri said.
Speaking to AFP in Cairo, another Hamas official said a general framework had been presented, and that the group was committed to achieving more than it did in the truce deal that ended the last major round of violence with Israel in 2012.
"We have a general framework, but have not declared point by point demands," he said.
"We need to build on the 2012 truce and move forward. We don't want to go back."
Masri told AFP that "Arab countries and Islamic countries and Western countries" were involved in discussions about a truce, but declined to give details.
He said Hamas was prepared to continue fighting and was ready for a "long, drawn-out battle."
The fighting entered its seventh day yesterday, with international pressure for a truce growing, but no sign of a concrete mediation channel or formula to end hostilities.
The Gaza-based Palestinian Centre for Human Rights (PCHR) said on Sunday that more than three-quarters of the victims were civilians.
The UN refugee for Palestinian refugees (UNRWA) has said more than a quarter of them were children.
"All indications are, and I find this particularly dramatic, that women and children make up a sizable number of the victims of the current strikes. Currently more than one quarter of the fatalities are children," UNRWA Commissioner-General Pierre Krahenbuhl said yesterday.
The bloodiest day so far was Saturday when 56 people were killed in a series of deadly strikes, Qudra said.
No Israelis have been killed, although three people in the Jewish state have been seriously wounded since the start of the operation, medics said.