Qatari Prime Minister Sheikh Hamad bin Jassem al-Thani warned that Israel's deadly raids on the Islamist-controlled Gaza Strip must not go unpunished, state news agency QNA reported on Thursday.

"This vicious attack must not pass unpunished," QNA quoted the premier as saying at a Wednesday meeting in Saudi Arabia of the six Gulf Arab nations and Russia.

Arab nations demanded the U.N. Security Council condemn Israel's deadly attacks on Gaza at an emergency meeting late Wednesday, but the United States strongly defended Israel's military strikes.

Egypt and other Arab states called for the emergency meeting after Israel staged scores of air strikes on the besieged Palestinian territory, killing Hamas military commander Ahmed Jaabari.

Two more Gazans died as Israel pressed on with a major bombing campaign across Gaza on Thursday, raising the death toll to 15, and Palestinian fighters fired more than 250 rockets over the border, with two of them hitting the Tel Aviv area.

As Palestinian deaths from relentless air strikes on Gaza mounted, Defense Minister Ehud Barak gave the go-ahead for 30,000 reservists to be called up and the military said it was "in the process of expanding the campaign."

Egyptian President Mohamed Morsi decided on Wednesday to recall the ambassador to Israel after a series of air strikes in Gaza killed a top Hamas militant and six other people, his spokesman said.

Morsi decided to "recall Egypt's ambassador to Israel," spokesman Yassir Ali said in a statement broadcast on state television.

President Barack Obama said Wednesday the United States is encouraged by Syria's new opposition coalition but is not ready to crown it the sole legitimate representative of the Syrian people.

"We're not yet prepared to recognize them as some sort of government in exile, but we do think that it is a broad-based representative group," Obama told reporters at the first news conference since his re-election.

Israel sent a "clear message" to Hamas through the killing of its top military commander and is ready to widen its operation in Gaza if necessary, Israeli Prime Minister Benjamin Netanyahu warned on Wednesday.

"Today we sent a clear message to Hamas and other terrorist organizations, and if it becomes necessary we are prepared to expand the operation," he said in a televised address.

Ahmed Jaabari, who was killed in an Israeli air strike on a car in Gaza City on Wednesday, was one of the most elusive and highest-ranking members of Hamas' armed wing.

Israel's Shin Bet domestic intelligence agency confirmed it targeted him in a joint strike with the army, saying he had been "directly responsible for executing terror attacks."

The new head of Syria's opposition is a "very moderate" figure who inspires confidence, a leading activist was once imprisoned by the regime for waging an Internet campaign said on Wednesday.

"I am very optimistic because I have a lot of faith in Ahmed Moaz al-Khatib," Hanadi Zahlout, who was in Italy as part of a campaign organized by Amnesty International, said in an interview with Vatican radio.

Palestinian president Mahmud Abbas on Wednesday slammed a series of Israeli strikes on Gaza which killed a top Hamas commander and six others, demanding an immediate end to the bloodshed.

"President Mahmud Abbas condemned the Israeli aggression on Gaza," said a statement carried on the official WAFA news agency which was issued shortly after an Israeli strike hit a car in Gaza City, killing Hamas military chief Ahmed Jaabari.

Egypt's Foreign Minister Mohammed Kamel Amr condemned the Israeli air strikes on Wednesday that killed a top Hamas militant in Gaza and called for an "immediate stop" to attacks on the Palestinian territory.

Amr, in a statement, warned Israel against any "escalation and its possible negative effects on regional stability."