JERUSALEM - Israeli jets and ground troops hammered at Hamas targets in the Gaza Strip and Islamic militants fired barrages of rockets at southern Israeli cities Friday, ignoring a UN resolution calling for an immediate ceasefire after two weeks of combat.
  
The Israeli prime minister's office said the UN action was not practical, and senior cabinet ministers decided to press on with the offensive. Israel will stop only when it succeeds in ending rocket fire from the Hamas-ruled territory, the government said.

Hopes that Thursday night's UN Security Council resolution would end Gaza's worst fighting in decades were further tempered by dismissive remarks from Hamas, angry that it was not consulted during exhaustive diplomatic efforts at the world body.

The foreign minister for the Palestinian Authority, which was driven out of Gaza by Hamas in 2007, criticized both Israel and Hamas for not accepting the demand for a halt to fighting.

"Both have responded to the resolution in the same way, in total disrespect," Riad Malki said at UN headquarters in New York. He said the Security Council should enforce its resolution, perhaps by levying sanctions.

Israel launched a heavy air bombardment Dec. 27 in response to intensified rocket fire that has disrupted life in southern Israel. A week later, ground troops moved in, with artillery and tank fire that has contributed to a surge in civilian casualties that continued Friday on Gaza's ruined streets.

Seven members of the Salha family were killed by an Israeli air strike on their house overnight, militants said. On Friday, crowds in neat rows bowed in prayer in front of their bodies, wrapped in funeral shrouds and flags.

In a hospital in Beit Lahiya, a northern Gaza town that has been particularly hard-hit, doctors treated a young girl whose left arm was torn off at the shoulder. She lay on a stretcher with a terrified expression on her face.

Such scenes have triggered anger throughout the Islamic world and elsewhere. There have been daily protests in the Middle East and in Europe, where there also has been a rise in anti-Semitic attacks.

In Washington, Secretary of State Condoleezza Rice said it is difficult to protect civilians in a place as densely populated as Gaza.

"It's also an area in which Hamas participates in activities like human shields and using buildings that are not designated as military buildings to hide their fighters," she told reporters. "So it's hard."

In Geneva, the top UN human rights official called for an independent investigation of possible war crimes in Gaza for an incident in which Palestinians said Israeli forces shelled a house, killing 30 people.

Israel's military said it was not aware of the specific incident but would not have deliberately targeted the building.

By Friday evening, more than 20 Palestinians had been reported killed during the day, pushing the death toll for the two-week conflict to around 780, according to Gaza health officials who said at least half of those killed were civilians.

Thirteen Israelis have been killed -- four of them by militant rockets, the rest in battle in Gaza.

The Security Council resolution called for an immediate, durable and fully respected ceasefire, leading to the full withdrawal of Israeli troops from Gaza.

While the call was tantamount to a demand on Israel and Hamas to stop fighting, it did not require that Israel's troops withdraw until there was a durable ceasefire.

The resolution also urged UN member states to intensify efforts to provide guarantees in Gaza to sustain a lasting truce, including prevention of arms smuggling, a key Israeli concern.

A six-month truce unravelled in November, and Israeli officials have said that lull allowed Hamas to bring in more advanced weaponry through hundreds of smuggling tunnels snaking beneath the Gaza border from Egypt's Sinai Desert.

In Israel's first official response to the UN resolution, Prime Minister Ehud Olmert's office said more Hamas rockets fired Friday "only prove that the UN's decision is not practical and will not be kept in practice by the Palestinian murder organizations."

Senior cabinet ministers issued a statement saying the military offensive would continue to protect Israeli citizens.

Hamas also dismissed the resolution, and spokesmen expressed annoyance they were not consulted.

"Nobody consulted Hamas or talked to Hamas. Nobody put Hamas in the picture and yet Hamas is required to accept it. This is unacceptable," Mohammed Nazzal, a senior Hamas official based in Syria, told Al-Arabiya television.

Hamas has said it won't accept any ceasefire deal that does not include the full opening of Gaza's border crossings. The UN resolution emphasized the need to open all crossings, which Israel and Egypt have kept sealed since Hamas militants forcibly seized control of the territory 18 months ago.

Israeli leaders oppose that step because it would allow Hamas to strengthen its hold on Gaza.

In Lebanon, Hamas official Osama Hamdan told Al-Arabiya that the group "is not interested in it (the UN resolution) because it does not meet the demands of the movement."

Seven Hamas officials crossed into Egypt on Friday through the Gaza border crossing at Rafah, on their way to Cairo for Egyptian-hosted negotiations on a truce with Israel.

The Islamic militant group, which was behind suicide bombings that killed hundreds of Israelis in past years, has been largely shunned by western powers since coming to political power in 2006 Palestinian elections.

That isolation has only deepened since Hamas took control of the Gaza Strip in June 2007 in five days of fighting with the Fatah movement of Palestinian Authority President Mahmoud Abbas.

Moderate Arab governments as well as the U.S. and its allies in Europe have supported Abbas' government, which controls only the West Bank.

The division has complicated efforts to advance peace efforts and reach a ceasefire in the latest fighting.

Despite the cool reception to the Security Council vote, the foreign ministers of Germany and Spain planned to visit the region to promote the UN resolution.

Israeli military operations showed no signs of abating Friday, despite a three-hour lull in fighting that has been instituted for three days running to allow aid to reach Gaza's distressed people.

One Israeli air strike killed two Hamas militants and another unidentified man, while another flattened a five-storey building in northern Gaza, killing the seven members of the Salha family, including an infant, Hamas officials said.

Two Israeli missiles clipped the roof of a building housing the offices of Iran's English-language Press TV and a sister Arabic-language network, slightly injuring one person, the channel's correspondent, Ashraf Shannon, said. The military said it had no knowledge of any attacks in that area.

Heavy clashes were reported northeast of Gaza City as Israeli soldiers advanced under the cover of Apache helicopters firing machine guns.

Fares Alwan, 49, said he was eating with his family when their house came under fire.
  
"I took my kids and wife and started running away for cover," Alwan said. "We saw wounded people in the street while we were running."

Later Friday, some residents received recorded phone messages said to be from Israel's military warning of a planned escalation. A military spokesman said he had no knowledge of the calls.

Hamas rockets hit in and around two of the largest southern cities in Israel, Beersheba and Ashkelon, but no casualties were reported.

In Gaza's rubble-strewn streets, there was concern of a worsening humanitarian situation on the second day of a UN suspension of aid deliveries and the Red Cross restricted its medical operations to Gaza City, where it has a team assisting surgeons at the main Shifa hospital.

The decisions by the two organizations came after they said Israeli fire killed two contractors delivering aid for the UN and injured the driver of a Red Cross truck in separate incidents Thursday.

With just over half the territory's population of 1.4 million relying on the UN for food, UN officials said Friday that they planned to resume aid operations "as soon as practical," based on Israeli assurances that aid workers would be better protected.

Gaza's people have become increasingly desperate for food, water, fuel and medical assistance. One million people are without electricity and 750,000 are without running water, according to the UN Palestinian refugee agency.