Israeli tanks plunged deeper into Gaza and the fighting against Hamas led to a high toll of casualties and a doubling of displaced Palestinians to 40,000, as Gaza's bloodiest conflict since 2009 showed no signs of let-up.
The latest deaths include two girls aged two and six years old in Gaza's northern Beit Hanun and a 16-year-old in southern Gaza's Rafah. A 20-year-old man died in Khan Yunis also in southern Gaza.
The death toll in the conflict between Israel and Hamas, the Palestinian militant group ruling Gaza, today increased to 337 - nearly a fourth of them being under the age of 18.
Israel's ground operation followed 10 days of air strikes on Gaza, which failed to stop Hamas's rockets from reaching across the border.
Three Israelis, including a soldier, have also died since the Operation Protective Edge campaign began on July 8.
UN Secretary General Ban Ki Moon was to arrive in the region soon to revive a ceasefire between Israel and Hamas.
Ban's visit would aim to help Israelis and Palestinians "end the violence and find a way forward", UN political affairs chief Jeffrey Feltman said.
"Israel has legitimate security concerns, and we condemn the indiscriminate rocket fire from Gaza into Israel. But we are alarmed by Israel's heavy response," Feltman said.
Egyptian Foreign Minister Sameh Shukri today repeated a call for the two sides to adopt its cease-fire initiative, saying it is the only offer on the table.
However, Netanyahu has warned of a "significant expansion" of the offensive and Hamas said Israel would "pay a high price" for the invasion.
Hamas terrorists today attempted to infiltrate Israel via an underground tunnel and kill civilians in an Israeli community, a few kilometres from Gaza.
Troops killed a Palestinian militant who tunnelled into southern Israel, but others managed to withdraw into Gaza, an army statement said.
"Several terrorists infiltrated Israel through a tunnel from the central Gaza Strip," it said, adding that they fired a machine gun and anti-tank missile at an army patrol.
Troops "returned fire, killing a terrorist and forcing the rest back into Gaza."
Hamas use such tunnels to infiltrate Israel as it did in 2006 when soldier Gilad Shalit was kidnapped by the terrorist outfit.
According to UN Relief and Works Agency for Palestine Refugees(UNRWA), about 50,000 Palestinians are staying in UN shelters.