European Union foreign policy chief Catherine Ashton said Friday that Israel had the right to protect its people against Gaza rocket attacks but urged it to stick to a "proportionate" response.

Deploring the loss of civilian lives on both sides, Ashton said in a statement that "the rocket attacks by Hamas and other factions in Gaza which began this current crisis are totally unacceptable for any government and must stop."

Egyptian Prime Minister Hisham Qandil vowed Friday to intensify Cairo's efforts to secure a truce and end Israel's "aggression" in the Gaza Strip.

"Egypt will not hesitate to intensify its efforts and make sacrifices to stop this aggression and achieve a lasting truce," he said at a press conference in Gaza City's Shifa hospital after seeing some victims from the latest Israeli strike.

Gaza fighters fired rockets at both Jerusalem and Tel Aviv on Friday aiming for the Jewish state's political and commercial hearts, prompting Israel to call up thousands more reservists in readiness for a potential ground war.

The military wing of the Islamist Hamas movement which rules Gaza said it fired the rocket at Jerusalem, the first to strike the outskirts of the Holy City in the history of the Israeli-Palestinian conflict.

Saudi King Abdullah has called for reason and wisdom during a telephone conversation with Egyptian President Mohammed Morsi in which he discussed the latest clashes between Gaza and Israel, state news agency SPA reported.

The monarch, whose country is a heavyweight in the six-nation Gulf Cooperation Council, told Morsi "that things must calm down and reason and wisdom must reign over passionate reactions," SPA said late on Thursday.

Syrian troops bombarded southern districts of Damascus and the outskirts of the capital before dawn, according to the Syrian Observatory for Human Rights and activists on the ground.

Residents in Damascus were kept awake through the night with the sound of explosions rumbling in the capital, they told Agence France Presse.

The Israeli army started calling up 16,000 reservists on Friday, as officials said the Jewish state was preparing for a possible ground offensive into the Gaza Strip.

"They're distributing emergency call-up notices now, the process has started," an army spokeswoman told Agence France Presse.

U.S. senators got their first look Thursday at dramatic video footage of the attack on the U.S. consulate in Benghazi as they probed the government's response to the deadly September 11 assault in Libya.

Four Americans were killed in the attack including the U.S. ambassador, Chris Stevens, and President Barack Obama's administration is under fire over security at the consulate and for its evolving narrative about the assault.

Middle East peace envoy Tony Blair called on Hamas on Thursday to stop firing rockets from Gaza into Israel, saying that as long as it continued the Jewish state would act to defend itself.

"If the rocket fire carries on out of Gaza, targeted at Israeli towns and villages, then the retaliation will increase," the former British prime minister told Sky News television in London.

France raised the prospect on Thursday of providing Syria's rebels with defensive weapons as Turkey joined it and the Gulf Arab states in recognizing the newly unified opposition.

France said it would discuss its proposal to ease the European Union arms embargo on both sides in the 20-month-conflict with its partners in the 27-nation bloc, but Russia said any such move would be a violation of international law.

Israeli Defense Minister Ehud Barak on Thursday approved the call-up of 30,000 reserve soldiers, who can be called into action by the military at any point, the army's official spokesman said.

"We are in the process of expanding the campaign," Brigadier General Yoav Mordechai told Channel 2 television as Israel pressed a massive air campaign against Gaza militants.