A Palestinian family and an Israeli Bedouin father were among those killed on Saturday as the casualty toll from Israel’s ground campaign and rocket attacks from Gaza continued to rise.
The Bedouin man died and family members were injured when a rocket hit their campsite in south Israel, police said.
The Palestinian family of eight were among several killed as the death toll in Gaza rose past 340, officials said.
UN chief Ban Ki-moon is heading to the region to help mediation efforts.
The visit is aimed at helping Israelis and Palestinians “end the violence and find a way forward”, the UN said.
On Friday US President Barack Obama said he was “deeply concerned” about civilian losses in the conflict.
Israel launched ground operations in Gaza following 10 days of air strikes, which failed to stop Hamas firing rockets across the border.
Further rocket attacks on southern Israel were reported on Saturday.
The Israeli military said it killed a Palestinian militant after he infiltrated Israel through a tunnel from central Gaza.
The army said he was among several militants armed with machine-guns aiming to carry out a lethal attack on a nearby Israeli community.
An Israeli patrol repulsed the attack, forcing the militants back into Gaza. Two Israeli soldiers died in the incident, the Israel Defense Forces (IDF) said.
Reports said residents of the al-Bureij refugee camp in central Gaza received telephone warnings from the IDF telling them to evacuate on Saturday ahead of Israeli military operations.
Earlier, an air strike outside a mosque in the southern town of Khan Younis killed seven people.
US President Barack Obama spoke to Israeli Prime Minister Benjamin Netanyahu on Friday, underlining his support for Israel’s right to defend itself against Palestinian militants but warning against escalation in Gaza.
President Obama said “no nation should accept rockets being fired into its borders” but called on Israel’s military to conduct its operation “in a way that minimises civilian casualties.”
Mr Netanyahu has warned of a “significant expansion” of the offensive but Hamas, the Palestinian group that controls Gaza, said Israel would “pay a high price” for the invasion.
“The ground invasion is a bad move because it is going to kill more innocent civilians and would do no good for Israelis.” – Abdelraziq, business and management graduate, Gaza
“The ground invasion is a necessary evil. The last thing that Israel would like to do is to risk the lives of its own soldiers and the lives of innocent people, but we have to stop the firing of the rockets and destroy the tunnels.” – Doron Youngerwood, marketing manager, Modiin, Israel
At least 60 Palestinians are thought to have been killed since Israel launched the ground offensive in Gaza on Thursday.
At least 342 Palestinians – the vast majority of them civilians – have been killed since the start of the wider Israeli operation on 8 July, according to officials in Gaza.
The UN children’s agency, Unicef, told AFP news agency that at least 73 Palestinian children have been reported killed.
Three Israeli soldiers and two Israeli civilians have been killed since 8 July and several Israelis have been seriously injured.
Israel says the ground operation is necessary to target a Hamas tunnel network, which the Israel military could not do only from the air.
UN officials say more than 50,000 Palestinians have sought shelter from the offensive.
In northern Israel’s city of Haifa, protests both for and against the Gaza offensive were held. Both demonstrations attracted hundreds of participants.
There were also clashes between supporters and opponents of the ground operation in Tel Aviv, Israeli news website Haaretz reported.