The United Nations Security Council has discussed the escalating violence between Israel and Palestinians in the Gaza strip at a closed emergency meeting, but took no action.
Egypt and other Arab nations called for the emergency meeting after Israel killed the Hamas military commander, Ahmed al-Jabari, during more than 20 air strikes on Gaza.
Palestinian diplomats say at least nine people - including Mr al-Jabari, another senior Hamas official and two children - have been killed and dozens injured in the attacks.
Israel says it was forced to act over mounting rocket attacks into its territory, with Israel's prime minister Benjamin Netanyahu saying he is prepared to widen the offensive.
The Palestinian envoy to the UN, Riyad Mansour, told the meeting that Israel was "vulgarly and publicly boasting about its wilful killing of Palestinians".
US Ambassador to the UN Susan Rice defended Israel's actions at the meeting, AFP reports.
"There is no justification for the violence that Hamas and other terrorist organisations are employing against the people of Israel," Mrs Rice told the session.
Highlighting Israel's claim that at least 768 rockets have been fired from Gaza this year, Mrs Rice told the council: "Israel, like any nation, has the right to defend itself against such vicious attacks."
Obama speaks to leaders
The United States president Barack Obama has spoken to the leaders of Israel and Egypt and reiterated US support for Israel's right to self-defence in light of rocket attacks from Gaza, Reuters reports.
The White House says the president urged Mr Netanyahu to make every effort to avoid civilian casualties.
It says the president also spoke with Egypt's president Mohamed Mursi, given Egypt's central role in preserving regional security.
Israeli news media say three people died when a rocket fired from the Gaza Strip struck an apartment building in southern Israel.
It was the first report of Israeli fatalities since Israel launched an air assault a day earlier.