Israel urged 100,000 Gazans to flee their homes on Wednesday, but the warning was largely ignored despite an intensification of the military's nine-day campaign after Hamas snubbed a ceasefire effort.

As the punishing Israeli operation resumed pace, Palestinian leader Mahmud Abbas was to travel to Egypt and Turkey in search of regional support for an immediate end to the fighting after an attempt at an Egyptian-brokered truce collapsed.

So far, Israel's campaign, now in its ninth day, has killed 208 Palestinians, with a Gaza-based rights group saying over 80 percent of them were civilians.

In the same period, militants have fired more than 1,200 rockets at Israel, which on Tuesday claimed their first Israeli life.

Overnight, warplanes struck about 40 sites across Gaza, among them political targets, as militants also kept up their fire on Israel's coastal plain, with four rockets shot down over metropolitan Tel Aviv.

The air force also dropped flyers warning 100,000 in northeastern Gaza Strip to evacuate their homes ahead of an air campaign targeting "terror sites and operatives" in Zeitun and Shejaiya, two flashpoint districts east of Gaza City.

Anm identical message was sent to Beit Lahiya in the north, echoing a similar army warning on Sunday, when more than 17,000 residents of the north fled for their lives, most seeking refuge in UN-run schools.

As well as the flyers, residents also received texts and pre-recorded phone messages urging them to evacuate and not return until further notice.

"We issued a warning to the people to leave instead of becoming victims of the policy of Hamas which tries to protect their rockets with civilians,"  Israeli President Shimon Peres said at a joint news conference with Italian Foreign Minister Federica Mogherini.

"We're trying to defend our own people, as we must, and we're also trying hard not to hit innocent people in Gaza."

- Gazans defiant -

 But the warnings did not have any immediate effect, with only limited numbers seen leaving, as children picked up the flyers and played with them, an AFP correspondent said.

"They dropped these bits of paper from planes telling people to leave. Where should we go?" asked Faisal Hassan, a father of five who lives in Zeitun.

"I will not leave my house, whatever happens."

Hamas told residents to ignore the warnings, saying there was "no need to worry".

"This is part of the psychological war, intended to disrupt the domestic front," it said in a statement.

Israel's Prime Minister Benjamin Netanyahu vowed to step up the military campaign after Hamas dismissed an Egyptian ceasefire proposal, firing scores of rockets over the border despite the army holding its fire for six hours.

"This would have been better resolved diplomatically... but Hamas leaves us no choice but to expand and intensify the campaign against it," he said.

Although Israel would prefer a truce to putting boots on the ground, the security cabinet met overnight to discuss the possibility of a limited ground operation, army radio reported, saying ministers had approved plans to destroy Hamas's network of tunnels.

They also discussed the possibility of a limited ground incursion which would not initially involve entering towns of villages, it said.

- Air campaign limitations -

"Israel has no option but to continue the operation and intensify it," former national security adviser Giora Eiland told army radio.

"The main dilemma is over a ground operation," he said, explaining that only a ground operation could inflict "real destruction" on Hamas's network of underground tunnels.

"It looks like we're rolling in that direction, since air strikes have their limitations."

Meanwhile, the Palestinian president was expected to arrive in Cairo during the evening for talks over a ceasefire with the Egyptian leadership. He was due to travel to Turkey on a similar mission on Thursday, officials said.

Hamas said it had rejected the Cairo truce efforts because it had not been included in the discussions, but top official Mussa Abu Marzuq said the Islamist movement was still in discussions about a possible ceasefire. (AFP)