Israel and Hamas rebuffed a United Nations call for a cease-fire in the 14-day Gaza war on Friday, with Israel saying continued barrages of rocket fire from its adversaries made the United Nations resolution “unworkable.”

In a statement after a cabinet meeting, Prime Minister Ehud Olmert said the Israeli military would “continue acting to protect Israeli citizens and will carry out the missions it was given,” according to news reports.

Officials from Hamas dismissed the United Nations resolution, according to news reports, although one official said it was being studied.

In Beirut, a Hamas spokesman, Raafat Morra, said the resolution “does not suit us because it is not in the best interest of the Palestinian people,” Agence France-Presse reported.

As the war continued unchecked on Friday, the Israeli military said its forces attacked more than 50 targets in overnight despite the United Nations vote on Thursday night calling for “an immediate, durable and fully respected cease-fire.”

Israeli warplanes attacked launching sites and missile-manufacturing facilities, the military said, while witnesses reported seeing rockets fired out of Gaza into southern Israel. The casualty toll was not immediately known. One Israeli air strike destroyed a five-story building, killing at least seven people, Hamas security officials told The Associated Press.

The developments came as international aid groups lashed out at Israel, saying that access to civilians in need is poor, relief workers are being hurt and killed, and Israel is woefully neglecting its obligations to Palestinians who are trapped, some among rotting corpses in a nightmarish landscape of deprivation.

The latest accusation concerning the treatment of civilians came on Friday when the United Nations Office for the Coordinator of Humanitarian Affairs said Israeli shelling killed 30 people who had been ordered along with 80 others to evacuate their homes and gather in a single apartment house.

“The next day the house was shelled,” Allegra Pacheco, a spokeswoman for the United Nations office, told the BBC, quoting unidentified witnesses.

The United Nations agency said the house was located in the Zeitoun district of Gaza City, the same area where the International Committee of the Red Cross reported Thursday that its representatives found four small children cowering next to their mothers’ corpses on Wednesday.

In a rare and sharply critical statement, the Red Cross said it believed that “the Israeli military failed to meet its obligation under international humanitarian law to care for and evacuate the wounded.”

Israeli officials said that they were examining all the allegations, that they did not aim at civilians and that they were not certain that the source of fire that killed and wounded the United Nations drivers was Israeli.

“We do our utmost to avoid hitting civilians, and many times we don’t fire because we see civilians nearby,” said Maj. Avital Leibovich, chief army spokeswoman for the foreign media. “We are holding meetings with U.N. officials to try to work out a mechanism so that their work can go forward.”

She said that the army learned of the Red Cross allegations in a media report, and that the committee had not yet presented the evidence of what she called “these very serious allegations” to the army.

Earlier this week, members of an extended family, the Samounis, said they had been ordered to evacuate their homes in Zeitoun and gather in a single dwelling. The complaints by the United Nations agency on Friday apparently related to the same family, a reporter in Gaza said.

Initial reports about the incident on Monday said 11 members of the Samouni extended family were killed and 26 wounded, according to witnesses and hospital officials, with five children age 4 and under among the dead. But the death toll rose as more bodies were found. The Red Cross said on Thursday that Israel had denied its representatives access to the area for several days.

Separately, the United Nations declared a suspension of its aid operations after one of its drivers was killed and two others were wounded despite driving United Nations-flagged vehicles and coordinating their movements with the Israeli military. The United Nations secretary general, Ban Ki-moon, called for an investigation by Israel for a second time in a week of the more than 40 deaths near a United Nations school from Israeli tank fire on Tuesday.

The Red Cross also said it was restricting its operations on Friday after one of its trucks was hit by small arms fire.

At the United Nations , fourteen nations approved the Security Council resolution urging a cease-fire, with the United States abstaining. Secretary of State Condoleezza Rice said the United States abstained , which left it unclear how a cease-fire would be enforced, because it wanted to see whether mediation efforts undertaken by President Hosni Mubarak of Egypt would succeed. The United States did not veto the resolution because Washington supports its overall goals, she said.

The resolution called for a cease-fire that would lead to the “full withdrawal” of Israeli forces from Gaza, the passage of humanitarian aid to the Palestinians and an end to the trafficking of arms and ammunition into the territory.