The international community has called for an end to the escalating conflict.
Earlier, Israeli air strikes in Gaza killed 10 people in a refugee camp and, separately, destroyed a building that housed foreign media organisations.
Hundreds of Palestinian rockets were fired into Israel, causing one death.
The UN Security Council will meet on Sunday to discuss the situation. US envoy Hady Amr has arrived in Tel Aviv to take part in talks with Israeli, Palestinian and UN officials, and reinforce what US diplomats said was the need for a "sustainable calm".
Since the fighting began on Monday at least 145 people have been killed in Gaza, according to Palestinian officials, and Israel has reported 10 dead, including two children. Israel says dozens of militants are among the dead in Gaza, while Palestinian health officials say its death toll includes 41 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 - the Palestinian militant group that runs Gaza - began firing rockets after warning Israel to withdraw from the site, triggering retaliatory air strikes.