Mangled limbs wrapped in blood-stained rags were strewn across rooms in the school.
Run by the United Nations, the building was meant to be a refuge for more than 3,000 civilians fleeing the deadly conflict raging between Israel and Hamas in Gaza.
But shells hit it in the early morning hours as those inside slept, punching huge holes in the roof and killing at least 20 people, according to the Palestinian Health Ministry.
"We saw the shells when they hit and shrapnel was falling like rain," said Sanaa abu Gerard, a woman who witnessed the blasts. "I was so scared and the school filled with smoke. We poured water in our eyes just to see."
The deadly strike Wednesday underscores growing concerns that in Gaza, where fighting is taking place in densely populated areas, safe havens appear to be anything but safe.
It's the sixth time a facility run by the United Nations Relief and Works Agency (UNRWA) has been struck in the current conflict, intensifying questions about the tactics being used by both sides in areas crowded with civilians.
"People who go to these places expect that they go there because they will be safe," said Pierre Krahenbuhl, the commissioner-general for UNRWA. "And here is the confirmation that it appears that there is nowhere where you can be safe."
The United Nations said it thinks the rounds that hit the school, in the Jabalya refugee camp in northern Gaza, were fired by Israeli artillery. The Israeli military said it is reviewing what happened, acknowledging that it exchanged fire with militants in the area.
See the latest on "Early Start" at 5am ET.
MORE on CNN.com
A week after Malaysia Airlines Flight 17 was shot down over war-torn eastern Ukraine, dozens more coffins containing remains of victims of the crash were due to arrive in the Netherlands on Thursday.
They will follow the first 40 wooden caskets, which were flown in Wednesday and greeted by somber, moving tributes across the country.
A lone bugler sounding the traditional military farewell "Last Post" marked their arrival at a military base in Eindhoven.
The grieving nation then held a moment of silence to honor those killed in the crash of the jetliner - caught in a war in which they had no part.
The plane was downed last week by a suspected surface-to-air missile over eastern Ukraine, where groups of pro-Russian rebels are battling Ukrainian government forces.
In a reminder of the ongoing bitter conflict, rebels claimed responsibility for shooting down two Ukrainian military jets on Wednesday. The rebels have denied that they brought down Flight 17.
MORE on CNN.com
Fierce fighting between Israeli troops and Hamas militants continued near Gaza City on Monday as the death toll from the conflict rose above 500.
Heavy bombardment hit areas east of the city, particularly the neighborhood of Shaja'ia, where a large Israeli assault Sunday contributed to the deadliest day of the war so far.
As clashes escalated over the weekend, Hamas said it had captured an Israeli soldier - a claim Israel later denied.
With no sign of either side backing down in a conflict in which most of the victims have been civilians, U.S. Secretary of State John Kerry is due to arrive in Egypt on Monday to push for a cease-fire.
Speaking to CNN's "State of the Union" on Sunday Kerry said that the United States supports Egypt's initiative for a truce and "will work for a fair cease-fire."
The United States has "shown our willingness to try to deal with the underlying issues," but Hamas "must step up and show a level of reasonableness," he said.
"No country, no human being, is comfortable with children being killed, with people being killed, but we're not comfortable with Israeli soldiers being killed either or with people being rocketed in Israel," Kerry said.
Follow this developing story on CNN.com
Deadly clashes broke out after Israeli tanks drove into Gaza and launched a ground operation that escalates the conflict with Hamas.
The incursion Thursday night follows 10 days of Israeli bombardment of Gaza that has killed more than 250 people. Israel launched the aerial offensive last week, saying it aimed to halt the firing of Hamas rockets from Gaza into Israel.
Israeli Prime Minister Benjamin Netanyahu and Defense Minister Moshe Yaalon ordered the ground operation to destroy tunnels dug from Gaza into Israeli territory, according to a statement.
Thirteen Hamas militants used a tunnel earlier Thursday to launch an attempted attack in Sufa, near an Israeli kibbutz, but were stopped by Israeli soldiers, the Israel Defense Forces said.
The IDF said it had sent a "large" force into Gaza that includes infantry, tanks, artillery, combat engineers and intelligence units, with aerial and naval support.
CNN's Wolf Blitzer asked Mark Regev, Netanyahu's spokesman, whether Israel planned to occupy Gaza for a long time.
Regev didn't answer directly, but said Israel's goals are to "diminish" the Hamas military force and to show that it cannot attack Israel with impunity.
You can follow all the developments at CNN.com.
At least three mortars were fired from Gaza toward southern Israel on Thursday morning, some two hours after a temporary lull in hostilities went into effect to allow humanitarian supplies into the area.
The mortars fell in open areas and no injuries were immediately reported, the Israeli military said. Mortars are smaller and have a more limited range than rockets.
Israel, which said it would honor the cease-fire but not sit idle if attacked, did not immediately respond.
The five-hour long temporary halt in fighting went into effect at 3 a.m. ET, requested by the United Nations to offer a brief respite in a conflict that has killed more than 220 people.
Banks opened for the first time in 10 days in Gaza and residents poured into the streets.
Red Cross officials visited hospitals and damaged houses to assess medical needs, and worked with local officials to quickly fix water pipelines, which has left hundreds of thousands without water.
There were no reported air strikes since the cease-fire began. Still, the fear of death hung heavily over Gaza. The health ministry warned civilians to avoid gathering in squares.
"Should the humanitarian window be exploited by Hamas or other terror organizations for the purpose of launching attacks against Israeli civilian or military targets the IDF will respond firmly and decisively," the Israeli military said.
MORE on CNN.com
The Israeli Defense Forces said Wednesday that it warned residents of three areas in Gaza to vacate their homes because of its plans to carry out airstrikes on Hamas and other terrorist groups.
The IDF said it used recorded messages, text messages and leaflets to alert the populations in Beit Lahyia, Shuja'iya and Zeitoun, places where it said "a high volume of rocket fire at Israel has originated."
"We are all scared but we are force to live in this and there is nothing for us to do," said Abu Musbah, a, 21-year-old member of Islamic Jihad, one of the groups that is firing rockets at Israel. "The children are scared but we struggle to continue our lives."
He said he had already evacuated all of his family members from his house in Shuja'iya.
A woman in the southern Gaza town of Khan Yunis said some people had fled there from harder hit areas in the north and east of the territory, filling some homes with multiple families.
"Those who have family here have come," said the woman, who asked not to be identified for fear of repercussions from talking to the news media.
She said she believed other people were staying in their houses, regardless of warnings from lsraeli leaflets or other means.
These are their homes, they will not run, she said.
MORE on CNN.com
Israel says it has accepted an Egyptian proposal for a cease-fire with Hamas. But without the militant group signing up as well, there may be little hope of seeing an end to the near constant exchange of fire that has so far killed more than 190 Palestinians in Gaza.
The Israeli security cabinet met early Tuesday morning and released a statement that said, "The cabinet has decided to reply positively to the Egyptian initiative for a ceasefire at 9 a.m. (2 a.m. ET)."
The plan calls for all sides to cease hostilities in Gaza. It also calls for the opening of border crossings, once the security situation is stable, and for high-level talks among those involved.
Hamas officials did not immediately respond to the cabinet's decision. But since the cabinet's announcement, only one rocket was fired from Gaza into its territory, the Israeli military said.
Earlier, Hamas mocked the proposal in public, with a spokesman describing it as a "joke."
"We did not receive this declared paper from the Egyptians ... which means it's an initiative for the media. It's not a political initiative," said Osama Hamdan.
Speaking on CNN's "The Situation Room with Wolf Blitzer," he continued: "It's not really an initiative. It's not really an idea, what they are trying to do is to corner the Palestinians and to help the Israelis more."
Hamas' military wing, the Qassam Brigades, said it hadn't received any formal or informal request about a cease-fire. But it said it rejects the proposal, describing it as an initiative of "kneeling and submission."
MORE on CNN.com
One bomb dropped on a center for the disabled. Another wiped out 18 members of the same family.
By Monday morning, the death toll from nearly a week of Israeli airstrikes on Gaza had reached 172 - all of them Palestinians - with more than 1,250 wounded, according to Palestinian health authorities.
Israel has so far shrugged off international calls for a cease-fire, saying it will continue the offensive as long as the militant group Hamas keeps firing rockets into its territory.
And Hamas shows no sign of letting up after already launching almost 1,000 rockets at Israel.
Caught in the middle are the residents of Gaza. While the Israeli attacks have killed some militants, around 70% of the fatalities were civilians, according to the United Nations. Of the dead, more than 30 are children, the U.N. reported.
"All sides ... must respect the sanctity of civilian life," said Chris Gunness, spokesman for the United Nations Relief and Works Agency for Palestine Refugees.
MORE on CNN.com
Israel faced attack from a second front Friday, but it is unlikely that a rocket fired from Lebanon signifies the widening of a conflict that has left at least 100 dead in Gaza.
The rocket launched from Lebanon landed near the northern Israeli town of Metula, which sits right by the Lebanese border, and no damage or injuries have been reported. It was not immediately clear who fired the rocket.
An Israel Defense Forces spokesman said Israel holds the Lebanese government responsible for the attack, but concerns that Israel will face a two-front conflict are unlikely to be realized.
Hezbollah, which operates in Lebanon and is caught up in other conflicts in the region, probably does not have the appetite to start a war with Israel.
Thousands of rockets were fired from Lebanon into Israel during a war in 2006, but rocket attacks since then have been sporadic. Tensions are always high between Hezbollah and Israel, but Hezbollah's involvement in Syria's civil war means that a fight with Israel might not make sense.
Nonetheless, Israel responded with artillery that landed in the vicinity of the Lebanese town of Kfar Shouba. No casualties were reported, the Lebanese army said.
Israel continued to weather rocket attacks by the Palestinian group Hamas in Gaza, but virtually all of the casualties in the conflict have been suffered on the Gazan side.
Though menacing, nearly all the Hamas rockets have been intercepted by the Israeli air defense system or struck empty areas. Airstrikes by Israel in Gaza, in contrast, have been blamed for at least 100 deaths, including 22 children and 20 women, a spokesman for Gaza's Ministry of Health said.
Hospitals in Gaza are unable to take care of the wounded - who top 700 - and patients are being treated on the floors because emergency rooms are overcrowded, medical sources told CNN.
The same medical sources said that medicines are running low and that the scenes at the hospitals are not unlike the chaos witnessed at Syrian hospitals during its civil war.
CNN staff in Gaza reported there are rolling blackouts, and there are water shortages in some areas because airstrikes have damaged pumping stations.
The Israeli military, meanwhile, said that some 100 rockets were fired at Israel today, including one that was intercepted over the Tel Aviv metropolitan area.
MORE on CNN.com.
A new wave of Israeli airstrikes battered areas of Gaza early Thursday, continuing the deadly onslaught aimed at stopping militant rocket fire into Israel.
The days-long aerial bombardment of Gaza has killed 76 Palestinians, including women and children, and injured more than 500 since it began Monday, Palestinian officials said.
Israeli Prime Minister Benjamin Netanyahu said the offensive would be expanded and continue "until the firing at our communities stops and quiet is restored."
But there was no sign that Hamas and other militant groups in Gaza were backing down as rockets continued to streak over the border into southern Israel. No Israelis have been killed so far in the rocket attacks.
Some Israeli officials have hinted at the possibility of a ground offensive in Gaza, although questions remain about the government's appetite for such a conflict.
Netanyahu didn't specify what the expansion of the current operation, which began Monday, would entail, but he said Israel's military "is prepared for all possibilities."
President Shimon Peres, whose role is largely ceremonial and is not involved in setting policy, said in an exclusive interview with CNN's Becky Anderson that he believed a ground offensive "may happen quite soon" unless Hamas stops firing rockets at Israel.
"We warned them. We asked them to stop it," Peres told Anderson. "We waited one day, two days, three days and they continued, and they spread their fire on more areas in Israel."
While Peres was speaking on his own and his position may not outline an official government policy, Israeli Intelligence Minister Yuval Steinitz earlier told CNN that a ground operation "might become necessary."
Palestinian Authority President Mahmoud Abbas, meanwhile, convened an emergency meeting of his cabinet on Wednesday to discuss the crisis.
"This war is not against Hamas or another political party but it is against the Palestinian people," he told the media afterward. "What do you call this crime? What is this crime known under international law? To kill entire families, is this collective punishment?
"This is called collective genocide."
A Hamas spokesman, Sami Abu Zuhri, said Israel's threat to launch a "stupid" ground offensive didn't scare anyone, and fighters from Hamas' military wing were ready to face off with Israel's "coward" soldiers in Gaza.
MORE on CNN.com.