Both Israel and Hamas pledged to keep fighting Friday -- ignoring a UN Security Council resolution calling for an immediate halt to fighting in Gaza.
Just hours after the resolution received near-unanimous international support, Israeli jets continued to strike targets in Palestinian areas -- and Hamas launched more rockets into two nearby Israeli towns.
One of Israel's 30 airstrikes Friday destroyed a five-story building. Hamas officials said the attack killed at least seven people, including a baby. In all, 23 Palestinians were killed by Friday afternoon, pushing the death toll to 777 in the two-week-old conflict.
Gaza health officials have said that half of the dead Palestinians are civilians, including dozens of women and children. Thirteen Israelis have died.
Israeli Prime Minister Ehud Olmert said Friday that the military "will continue acting to protect Israeli citizens and will carry out the missions it was given."
In a statement released by his office, Olmert said the UN's call for a ceasefire was "not practical" at this time.
"The firing of rockets this morning only goes to show that the UN decision is unworkable and will not be adhered to by the murderous Palestinian organizations," he said.
Hamas spokesman Sami Abu Zuhri said the UN resolution didn't address issues affecting the Palestinian people.
"This resolution doesn't mean that the war is over," he told the Al-Jazeera satellite television network.
"We call on the Palestinian fighters to mobilize and be ready to face the offensive and we urge the Arab masses to carry on with their angry protests."
Even the Bush administration, staunch Israel supporters, voiced concerns about the humanitarian situation in Gaza on Friday.
But U.S. officials blamed Hamas for the Palestinians suffering and said that Gaza's dense population makes it difficult for Israel to avoid civilian casualties.
On Thursday, the UN Security Council passed the resolution by a vote of 14-0. The United States abstained from the vote, saying it was awaiting the outcome of Egyptian-mediated talks between Hamas and Israel.
Prime Minister Stephen Harper repeated his position on Friday that Canada supports an "effective and durable" ceasefire that is agreed to by both sides.
The U.N. halted aid deliveries into Gaza for the second day due to security concerns. Half of the territory's population is dependent on the U.N. for food. The Associated Press reported that Palestinians could still get food and medicine on Friday, if they were willing to take the risk of going to relief centres.
On Thursday, Israeli tank fire killed a U.N. aid worker in truck -- and the Red Cross reported a similar attack that injured one of its drivers.
U.N. relief agency spokeswoman Elena Mancusi Materi said aid workers would resume efforts only after Israel promises not to shoot at their vehicles.
World Vision's national director in Jerusalem, the West Bank and the Gaza Strip, said it's been "very difficult" to get aid into Gaza.
Charles Clayton told CTV's Canada AM on Friday that emergency materials such as blankets, candles and food supplies are most needed by Gazans.
"People only wake up to the problem when there are huge numbers of deaths," he said. "At the moment, there are huge numbers in Gaza who are suffering terribly -- starvation, malnutrition, lack of water, lack of sanitation, lack of freedom, no safety."
Clayton said his organization is "desperately" calling for a ceasefire so that ordinary families inside Gaza can get assistance.
CTV's Tom Kennedy, reporting from Jerusalem, said there were about 50 Israeli air strikes on Gaza overnight.
"This morning Israeli artillery shells are continuing to fall on the city and surrounding areas in Gaza," Kennedy told CTV's Canada AM.
Hamas also showed no signs of letup Friday as it continued to fire rockets into southern Israel.
Kennedy said there is widespread support within Israel for the offensive in Gaza because of the frustration over Palestinian rocket attacks.
Some observers have said that any Israeli politician who agrees to a ceasefire "may as well pack up his or her bags and leave the country," Kennedy said.
With files from The Associated Press
