A United Nations school crammed with people displaced by Israel's war with Palestinian militants was hit in shelling in the Gaza Strip early Wednesday, killing at least 16 people and injuring scores more, local officials said.
The strike happened the day after Israel unleashed some of the most intense bombardments of the 23-day operation against Hamas, which controls the narrow coastal enclave.
More than 100 people were killed in Israeli shelling across Gaza on Wednesday, lifting the Palestinian toll for the campaign to more than 1,300, said Ashraf Kidra, a Health Ministry spokesman.
Three Israeli soldiers were also killed while uncovering a tunnel shaft leading from a home in southern Gaza, the military said in a statement. Both the house and the tunnel were booby-trapped with two explosive devices that detonated on the soldiers, the statement said.
Since the operation began, at least 56 soldiers have been killed on the Israeli side along with three civilians who died in mortar and rocket fire from Gaza.
With fighting escalating, the Israel Defense Forces announced a four-hour cessation of hostilities beginning at 3 p.m. local time Wednesday to give rescue workers time to evacuate the dead and the injured, and civilians trapped in combat zones time to escape. But they said it would not apply to areas where Israeli troops are "active."
Hamas spokesman Sami Abu Zuhri dismissed the announcement as a "a media stunt," saying the truce had no value because it excluded zones along the border with Israel from which the group wished to evacuate wounded.
A few minutes after the unilateral truce took effect, a volley of rockets was launched from Gaza toward the Israeli communities of Ashkelon and Ashdod. In Gaza City, thundering explosions continued into the evening.
Before Israel's "humanitarian window" closed, word came of an airstrike in a crowded shopping area on the east side of the city. At least 15 people were killed and more than 150 injured, Gaza health officials said.
More than 240,000 people have been displaced by the fighting, according to the latest United Nations estimates. Many have sought shelter in schools operated by the U.N. aid agency for Palestinian refugees.
The school hit Wednesday is located in the Jabaliya refugee camp, a warren of narrow winding streets north of Gaza City and one of the most densely populated parts of the strip.
Israel said it had dropped leaflets and sent recorded phone messages to residents there urging them to evacuate Tuesday. But many of those sheltering at the school said they did not receive the warnings, and in any case had nowhere else to go.
Najwa Abu Oda, 46, said her house was destroyed by shelling in the northern town of Beit Hanoun, a focus of Israel's campaign to dismantle rocket installations and destroy cross-border tunnels used to attack its citizens. She said she had hoped her family would be safe at a local U.N. school.
But the facility was hit by a series of explosions last week, killing at least 16 people who were sheltering there. So they moved south to the school in Jabaliya, she said.
Her 16-year-old son and 50-year-old son-in-law were sleeping in the courtyard when shells started crashing into the school early Wednesday, hitting two classrooms and the bathroom. Both were rushed to a local hospital with shrapnel wounds.
Hours later, the rest of the family was still sitting on the edge of the courtyard, as journalists and dazed survivors surveyed the damage. Blood-soaked clothes and upended furniture were visible amid the rubble in one classroom.
"Where do they want us to go?" Abu Oda asked? "We have no other place."
The Israeli military said it was looking into the incident.
Israeli officials have said that their forces do not target schools and have accused Palestinian militants of putting civilians at risk by operating among them.
The Israel Defense Forces acknowledged Sunday that one of their mortar rounds landed in the courtyard of the school that was hit last week, but said there was no one there at the time. Israeli officials had previously said that fierce clashes were taking place in the area, suggesting that the casualties might have been caused by an errant rocket fired by Palestinian militants.
The Israeli military said it targeted 75 sites in Gaza overnight, including five mosques that it said were used by militants to conceal weapons, house tunnel shafts and as lookout posts.
More than 2,670 rockets and mortar rounds have been fired at Israeli civilians since the operation began, according to the country's military. About 280 others missed their targets and landed in Gaza, it said.
Special correspondents Batsheva Sobelman in Jerusalem and Maher Abukhater in Ramallah contributed to this report.