Israeli artillery shells slammed into U.N.-run school sheltering evacuees from the Gaza conflict early Wednesday, killing at least 20 people and wounding dozens of others as they slept, according to Palestinian health officials and the U.N. agency in charge of the school.
The Israeli military later announced that it would implement a temporary humanitarian cease-fire in the Gaza Strip between 3 p.m. and 7 p.m. Wednesday. The cease-fire would not apply to areas in which Israeli military is currently operating, it said.

The U.N. Relief and Works Agency (UNRWA), which operated the school-turned-shelter in the territory’s Jebaliya refugee camp, said the facility was shelled by Israeli forces and condemned what it called a serious violation of international law. The Israeli army said it was investigating.
In a statement, UNRWA called the attack on the Jebaliya Primary School for Girls “a source of universal shame.”

“Last night, children were killed as they slept next to their parents on the floor of a classroom in a U.N.-designated shelter in Gaza,” the agency said. “We have visited the site and gathered evidence,” it added. “We have analyzed fragments, examined craters and other damage. Our initial assessment is that it was Israeli artillery that hit our school, in which 3,300 people had sought refuge.”
UNRWA spokesman Chris Gunness said it was the sixth time that one of the organization’s schools has been struck.

Israel has said some of the facilities are used by Hamas militants to store rockets that are later fired on civilian populations in Israel. Gunness refused to comment on this, even though the United Nations has said it found rockets hidden on its premises.
A spokesman for the Israeli army, Capt. Eytan Buchman, said Israeli forces in Gaza came under mortar fire earlier Wednesday from a point near the school in the Jebaliya camp and responded toward the source of the fire. The incident is being reviewed, he said.

Gaza Health Ministry officials said 40 people were killed in Israeli strikes overnight and more than 110 injured as Israel pressed ahead with its escalated campaign against the coastal enclave. The Palestinian death toll rose to more than 1,270 people, most of them civilians, according to the United Nations. Israel has lost 53 soldiers in the conflict, its largest toll since its 2006 war in Lebanon. Mortar and rocket attacks from Gaza have also killed two Israeli civilians and a Thai worker.

The school strike came one day after some of the heaviest Israeli bombardment in the conflict, during which Israel disabled Gaza’s only electricity plant, leaving the crowded territory’s 1.8 million residents with no electricity or running water.
Israeli Prime Minister Benjamin Netanyahu warned his country in a televised address Monday evening to be prepared for a prolonged campaign against Hamas, the Islamist militant group that rules the Gaza Strip. Israel has said it cannot stop until it dismantles a network of tunnels it says are used by militants to infiltrate into Israel from Gaza.

Witnesses at the Jebaliya Primary School for Girls said shelling struck a classroom where some 50 people, mostly women and children, were sleeping. The classroom’s roof was ripped apart. Most of the dead, however, were young men, who had woken for the traditional Muslim dawn prayer, said Moen al-Masr, a doctor at the Kamal Odwan hospital. He said 10 people were seriously injured in the attack.

“We found people torn to pieces,” said Allah al-Bes, 33, who was seeking refuge at the school with his wife and three boys. “It was like hell.” Bes and his family went to the school after an earlier attack on a U.N.-run school in Beit Hanoun. “We have learned no place is safe in Gaza,” he said.
Expanding its list of targets Tuesday, Israel destroyed the family home of Ismail Haniyeh, the top leader of Hamas. Other airstrikes hit Hamas’s al-Aqsa television broadcast center, a finance building and the homes of local mayors. Haniyeh is in hiding and his whereabouts are unknown.

Along the coast of the seaside enclave, Israel also hit a fishing harbor near hotels where scores of international journalists are staying. Airstrikes also hit the Rafah area, along Gaza’s border with Egypt, according to local news reports.
Israel said Tuesday afternoon that its forces had come under attack from militants in Gaza emerging from a concealed tunnel. A gun battle followed, although no details were immediately available. The Israeli military reported a similar infiltration Monday evening, saying five soldiers were killed in a battle with militants from Gaza who entered southern Israel via a tunnel. At least one militant died.
Rocket barrages from Gaza sent people in Tel Aviv, Israel’s commercial capital, scurrying to shelters early Tuesday.

In the center of Gaza City, an airstrike obliterated al-Amin Mohammed Mosque opposite the Gaza home of Palestinian Authority President Mahmoud Abbas. In 2007, when it seized control of Gaza, Hamas took over the home and used it to house senior leaders. The militants handed it back to Abbas earlier this year after Hamas and the Palestinian Authority reached an agreement on forming a unity government.

Neighbors said that the mosque was not Hamas-run and that anyone could pray there.
“This is a mosque for the public, and I am one of the public,” said Muhammed Abdu, a 45-year-old engineer, as he looked at a cavernous hole filed with debris where the mosque had stood. “This is all part of a strategy to burn Gaza down.”
He said the attack underscored the need for a cease-fire. But like many Gazans interviewed over the past two days, Abdu said the core Palestinian demand of lifting an economic blockade by Israel and Egypt should be met.

“To bring milk in for your child, is that a crime?” Abdu asked. “To have an open crossing so that you can leave for medical care, is that a crime? To travel outside for your business, is that a crime?”
Near the Nusairat refu­gee camp, in the middle of the Gaza Strip, the shattered fuel tank of the territory’s primary power plant continued to emit flames and thick plumes of smoke hours after being hit.

The plant is Gaza’s primary source of electricity, powering sewage treatment systems, water pumps and hospitals, said Dardasawi, the Palestinian official. It is especially important, he added, because six of eight electricity supply lines that run from Israel were damaged. Egypt also supplies some electricity, he added, but hardly enough to power the border town of Rafah.

“This is like a time bomb,” said Dardasawi, referring to the potential humanitarian crisis.
Outside Haniyeh’s wrecked house in the Beach Camp neighborhood of Gaza City, neighbors gathered Tuesday to express anger. Not far away, 10 people, including seven children, were killed in an attack Monday that Hamas and Israel blamed on each other.
Neighbors said Haniyeh and his family had not lived in the house since the conflict erupted. The dwelling, they said, was hit around 2 a.m., and no one was killed or injured. Israel’s military, they said, phoned a neighbor around 1:45 a.m. with instructions to tell other residents on the street to evacuate.

But most fled when they heard two small missiles from an Israeli drone strike the house, presumably as a warning, residents said. Minutes later, a powerful airstrike, possibly by an Israeli F-16, brought down the house in a pinpoint attack that did little serious damage to the surrounding homes in this densely packed enclave.
Some neighbors said Tuesday that the attack made them support Hamas even more and that they would never accept a cease-fire until Palestinian demands were met.

“Israel said it wouldn’t target him because he is a politician,” said Wasifiyah Hassonehm, 53, who lives two houses down. “Now, they are targeting everyone — the politicians, the civilians, everyone.”
In an e-mailed statement to journalists, Haniyeh said the attack would not deter Hamas. “Destroying our homes will not change our attitude, but it will strengthen it,” he said.