JERUSALEM — Israel and Hamas went back and forth Sunday over proposals for a new cease-fire in the fighting in the Gaza Strip, and Israel sought to bolster its claim that its forces were not responsible for the deaths of 16 Palestinians reportedly killed in an attack on a U.N. school.
Palestinians who brought their dead and wounded relatives to a Gaza hospital after the attack Thursday said that hundreds of people who sought shelter in the school had gathered in its courtyard, believing that buses were on the way to take them somewhere safer. Then a number of munitions fired by Israeli forces hit the school, they said, killing and wounding scores of people.
The United Nations also reported the attack but said it could not confirm the source.
On Sunday, Lt. Col. Peter Lerner, an Israeli military spokesman, acknowledged that an errant mortar round fired by Israeli troops had exploded in the school’s courtyard that afternoon but said the yard had been empty at the time. He provided a video with 10 seconds of black-and-white footage shot by an Israeli drone that showed a blast in what appeared to be an empty courtyard.
“It is extremely unlikely that anyone was killed as a result of that mortar,” he said.
It was not immediately possible to reconcile the accounts.
A visit to the school two days after the attack revealed a small crater from a blast in the courtyard, shrapnel scars on the school walls and large blood spots on the ground near the blast site. Lerner said the mortar strike shown in the video was the only Israeli ordnance that hit the school that day. The video did not include a time code, but Lerner said it was shot between 2 and 4 p.m. The United Nations said the attack had taken place at 2:55 p.m.
The diplomatic push for a cease-fire continued late Sunday as U.N. officials announced that the Security Council planned to meet at midnight to issue a statement supporting the call for a humanitarian cease-fire in Gaza.
Earlier in the day President Barack Obama called Prime Minister Benjamin Netanyahu of Israel and expressed his growing concerns about the rising death toll and urged Israel to embrace an immediate truce. Secretary of State John Kerry also kept up his efforts to attain a long-term cease-fire, even as Israel and Hamas, the militant group that governs Gaza, seesawed on whether to begin a new humanitarian lull in the fighting.
Early Sunday, Israel said its military was resuming its offensive in Gaza because of rocket fire by Hamas during what was supposed to have been a cease-fire from midnight Saturday until midnight Sunday. Huge clouds of smoke from explosions could be seen rising from the eastern neighborhoods of Gaza City near the border with Israel, and ambulances rushed new cases to Shifa Hospital in Gaza City.
But by afternoon, Hamas had called for a new 24-hour pause, saying it was responding to a request from the United Nations and because Palestinians were preparing for the Eid al-Fitr holiday, to be observed Monday.
There was no immediate response from Israel, but fighting appeared to slow around Gaza in the evening. The Israeli military said it bombed 40 sites and targeted six militants Sunday, while Gaza fighters fired scores of rockets into Israel, most of which fell in open areas.
Both sides appeared to want to dictate the timing of any lulls.
In an interview on the “Fox News Sunday” program, Netanyahu said, “Israel is not going to let a terrorist organization determine when it’s convenient for them to fire at our — at our cities, at our people, and when it’s not, when they can restock.”
Professor Shmuel Sandler, a political scientist at Bar-Ilan University near Tel Aviv, said that Hamas, too, “feels it cannot accept even a humanitarian cease-fire when it is not the one that sets the time.”
Some Israeli politicians have talked of the possibility of escalating the offensive against Gaza’s militant groups as intense international efforts over the weekend to press for a broader cease-fire appeared to have failed.
More than 1,000 Palestinians have been killed in Gaza, most of them civilians, according to the Palestinian Health Ministry and monitoring groups. It said that at least 10 people were killed by Israeli fire Sunday and that three more had died from injuries.
An Israeli reserve soldier was killed overnight by mortar fire from Gaza, according to the military, bringing the number of Israeli soldiers killed since the beginning of the campaign, on July 8, to 43. Three civilians in Israel have also been killed.