In a fiery speech broadcast across the Arab world, a top Hamas leader said Israel's war in Gaza has killed the last chance for a settlement and negotiations between the two warring factions.

Damascus-based Hamas leader Khaled Mashaal condemned Israel's two-week offensive in the Gaza strip, which the United Nations estimates has killed hundreds of Palestinian civilians, including women and children.

In a speech aired on Al-Jazeera, Mashaal called the Israeli offensive a "holocaust." He called for an immediate end to the Israeli airstrikes and ground operation in the territory. He said Palestinians want Israel to remove its forces from Gaza and lift its blockade.

Mashaal's comments came as the Israeli air force dropped more pamphlets into the area on Saturday to warn residents of its plans to escalate the offensive.

The leaflets say Israel plans to begin a "new phase in the war on terror" and ramp up an operation that is aimed at halting rocket fire from Gaza into southern Israel.

The warning came as Israeli aircraft pounded more than 40 Hamas targets, including 10 rocket-launching sites, weapons-storage facilities, smuggling tunnels and an anti-aircraft missile launcher.

Earlier Saturday, a shell from an Israeli tank killed nine people as they sat outside their home in the northern Gaza city of Jebaliya, and a woman was killed by an air strike in the southern town of Rafah.

On the ground, 15 militants were killed in fighting with Israeli troops inside Gaza, Israeli military officials said.

Some of Saturday's heaviest fighting occurred on a coastal road north of Gaza City that militants use to fire rockets into Israel.

Israel has largely taken control of the road. However, militants continue to strike from hidden positions in the area.

Hamas had ceased firing rockets into Israel overnight, but by early Saturday morning at least 10 had landed in southern Israel, the Israeli military reported.

International Pressure

The fighting in Gaza continued despite calls for a ceasefire from an international community that is becoming increasingly outraged at the increasing number of casualties.

Palestinian Authority president Mahmoud Abbas urged both Israel and Hamas to agree to an Egypt-brokered truce.

"If any party does not accept it, regrettably it will be the one bearing the responsibility, and if Israel doesn't want to accept, it will take the responsibility of perpetuating a waterfall of blood," Abbas told reporters.

So far, neither side has indicated they are willing to accept a truce.

On Thursday, the UN Security Council passed a resolution calling for an immediate ceasefire and the withdrawal of Israeli troops from Gaza.

Israel has dismissed the resolution as impractical, while Hamas complained that it has not been consulted during ongoing diplomatic talks.

UN Secretary General Ban Ki-moon told Israeli Prime Minister Ehud Olmert on Friday that he was disappointed that both sides were ignoring the UN resolution.

Israel has said that any ceasefire must contain assurances that Hamas will halt rocket attacks and end the smuggling of weapons along the Gaza-Egypt border.

Hamas officials want Gaza's border crossings -- which have effectively been sealed since Hamas took control of the region 18 months ago -- re-opened.

Humanitarian crisis

The Israeli offensive has already killed more than 800 Palestinians, as many as half of whom may be civilians, according to estimates by Palestinian and UN officials.

Thirteen Israelis have been killed: four by rockets fired into Israel and the rest in battles in Gaza.

Meanwhile, international aid agencies fear a looming humanitarian crisis in the territory of 1.4 million people.

The UN estimates that nearly two-thirds of the population is without electricity, while half do not have running water.

The Israeli military said it would halt fire for three hours on Saturday so civilians could leave their homes to stock up on badly needed supplies.

However, some aid groups would like a longer ceasefire in order to distribute food and other aid to more civilians.

Officials with Save the Children say that three hours only allows them to reach about 9,500 people, far short of the 150,000 it usually serves.

"Even the U.S. is appealing to Israel to make these periods of calm even longer so that the UN can properly distribute food to the hundreds of thousands of people who need it -- (and) so that medics and the Red Cross can get to places where they haven't been able to get to before to check on wounded," CTV Middle East Bureau Chief Janis Mackey Frayer told Newsnet from Jerusalem on Saturday.

Any aid that is delivered comes from existing supplies in Gaza. The UN halted aid shipments through Israeli-controlled border crossings on Thursday after a UN truck driver was shot and killed.

With files from The Associated Press