Demonstrations against Israel's military action in Gaza and in support of Palestinians took place in Tehran and 700 other Iranian cities after Friday Muslim prayers, news agency ISNA said.

Protesters chanted "death to America" and "death to Israel" in the capital, in demonstrations called for by the authorities.

French President Francois Hollande said Friday he was seriously concerned by the escalation of violence in the Gaza Strip and had spoken to Israeli and Egyptian leaders a day earlier.

"I am seriously concerned by what is happening in the Gaza Strip, both by the rocket attacks on Israel and the reprisals that this escalation may bring," Hollande told reporters at a joint press conference with Poland's President Bronislaw Komorowski, who called for a resumption of peace talks between Israel and the Palestinian Authority.

Thousands of angry Palestinians rallied across the West Bank on Friday, urging Hamas militants to "bomb Tel Aviv" as Israel pursued a relentless air campaign on the Gaza Strip.

More than 1,000 protesters gathered in central Ramallah, shouting slogans of support for Gaza's Hamas rulers, and waving the Islamist movement's green flag, Agence France Presse correspondents said.

Saudi Arabia urged its citizens to stay away from public gatherings and universities in Jordan, where riots over fuel price hikes have left one person dead and 71 wounded, state news agency SPA reported.

The kingdom's embassy in Amman "warned Saudi employees and students in Jordan from going to public squares or approaching sites of gatherings and demonstrations," SPA said late on Thursday.

German Chancellor Angela Merkel on Friday called on Cairo to use its influence on Hamas to ease tensions in the Gaza Strip as Egyptian Prime Minister Hisham Qandil visited the violence-wracked area.

"The federal chancellor calls on the Egyptian government to use its influence on Hamas to push it towards a moderation of the violence," Merkel's deputy spokesman Georg Streiter told a regular government news conference.

Tunisian Foreign Minister Rafik Abdessalem will visit Gaza on Saturday, the presidency said, in a statement denouncing Israel's "barbaric aggression" on the Palestinian enclave.

"The presidency of the republic has informed the president of the government in Gaza that a high-level delegation headed by the foreign minister and including the (Tunisian) president's chief of staff will be sent to Gaza tomorrow," it said.

British Foreign Secretary William Hague indicated on Thursday he would decide within days whether to officially recognize the new Syrian opposition after "encouraging" talks with its leaders in London.

Hague said he had pressed Ahmed Moaz al-Khatib and his two deputies, who are on their first visit to a Western capital since a united Syrian opposition was formed last weekend, on the need to be inclusive and to respect human rights.

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.