Israeli air strikes killed 35 Palestinians on Monday, hiking the Gaza death toll to 103 as global efforts to broker a truce to end the worst violence in four years gathered pace.

In the latest bloodshed, an Israeli missile killed a senior Islamic Jihad militant in a strike on a Gaza City tower housing Palestinian and international media, the Israeli army and militants said.

Leading Republican Senator John McCain suggested Sunday that President Barack Obama should send Bill Clinton as a special envoy to try to negotiate peace between Israel and Hamas.

"The United States should obviously be as heavily influential as they can," McCain told CBS television, referring to the bloody conflict that has raged since Wednesday between Israel and the Gaza Strip's Islamist rulers.

Senior U.S. Senator Carl Levin criticized Egypt's "weak" efforts Sunday to pressure its ally Hamas to reduce tensions in the bloody conflict between Gaza's Islamist rulers and their enemy Israel.

"It's pretty weak so far from what I can tell. The Egyptians have a real interest here in the region not exploding and the peace agreement continuing to be abided by," said Levin, who chairs the Senate Armed Services Committee.

French Foreign Minister Laurent Fabius said on Sunday a ceasefire between Israel and Gaza militants was an urgent necessity and France was willing to help broker a truce.

"War is not an option, it is never an option," he told journalists in Tel Aviv. "There are two key words: urgency and ceasefire," he said.

Syria's regime on Sunday slammed as "hostile" a French decision to host an opposition ambassador, as its forces bombarded southern districts of the capital and clashes raged nationwide.

France on Saturday invited the National Coalition, the newly formed Syrian opposition bloc, to send an envoy to Paris, after President Francois Hollande met its leader, Ahmed Moaz al-Khatib.

Palestinian President Mahmoud Abbas called on Sunday for Palestinians to stage peaceful demonstrations against Israel's military offensive on Gaza militant groups.

"I call on the Palestinian people to intensify their peaceful demonstrations in the streets against the Israeli aggression in Gaza," he said at a meeting with the Palestinian leadership.

Khalil al-Dallu screams. "They said Mohammed was alive!" he shouts as emergency workers pull the body of a young man from a Gaza City home leveled by an Israeli strike on Sunday.

His face quickly crumples into tears as the emergency staff tell him that his cousin is in fact dead -- one of six members of the Dallu family killed when an Israeli missile struck the Nasser neighborhood, flattening the three-story building where they lived.

The Israeli government on Sunday admitted it had become the victim of a mass cyber-warfare campaign with millions of attempts to hack state websites since the start of its Gaza offensive four days ago.

Speaking ahead of the weekly cabinet meeting, Israeli Finance Minister Yuval Steinitz said the government was now waging war on "a second front -- of cyberattacks against Israel."

Russian Foreign Minister Sergei Lavrov will seek a meeting of the so-called Middle East quartet over the Gaza crisis when he holds talks with U.S. Secretary of State Hillary Clinton in Asia this week, the Russian news agency Ria Novosti said Sunday.

Russia has condemned as "disproportionate" the Israeli blitz on the impoverished Gaza Strip, where 64 Palestinians have been killed while three Israelis have been killed in rocket attacks by Palestinian militants since Wednesday.

An Israeli official landed in Cairo on Sunday for Egypt-mediated truce talks with Hamas to end the Gaza conflict, Egyptian security officials said.

The official landed in a small plane at 1100 GMT and was quickly escorted away by intelligence personnel, the security officials said.