The attacks occurred as a high-level Israeli delegation was visiting Egypt in an attempt to review truce talks in Gaza.
At least 15 people have been killed in Israeli airstrikes on a school housing displaced Palestinians in central Gaza, the Gaza government's media office reported.
Many other people were injured in the attack on the Hamama school in the Sheikh Radwan neighborhood of Gaza City, the official Palestinian news agency Wafa reported on Saturday.
Reporting from Deir el-Balah in central Gaza on Saturday, Al Jazeera's Hani Mahmoud said at least three bombs were dropped on the school as rescuers and volunteers inside the facility tried to help people escape from beneath the rubble.
“These three bombs destroyed the facility completely. This is a tactic that the Israeli army has used extensively in the past. The army drops a bomb that partially destroys the facility, specifically the evacuation centres, killing several people, and then, within a few minutes, drops other bombs,” he said.
The Israeli military said the school was being used as a command center by Hamas, the Palestinian group that rules Gaza, to hide fighters and manufacture weapons.
Hamas has denied Israeli accusations that it operates from civilian facilities such as schools and hospitals.
The group condemned the Israeli attacks on the school and said in a statement that “the occupation army uses lies as a pretext to attack defenseless civilians in Gaza.”
In footage verified by Al Jazeera, victims of the Israeli strikes are seen arriving at Al-Ahli Hospital.
Among the injured were children, some of whom appeared to be unconscious, as medical staff desperately tried to treat them.
Scenes at the hospital were chaotic, with some of the wounded lying on the floor while grieving Palestinians lined the corridors.
According to the testimony of one of the injured, the raids were carried out without prior notice.
Earlier on Saturday, Israeli strikes in the Gaza Strip killed six people in a house in the southern Rafah area and two others in Gaza City, Gaza health officials said.
The Israeli military said its forces targeted Hamas fighters and destroyed Hamas infrastructure in Rafah and elsewhere in the strikes.
In the occupied West Bank, two Israeli strikes killed nine fighters, including a local Hamas commander, on Saturday, Hamas said.
A Hamas statement added that one of the dead was a commander of its Tulkarem brigades, while its ally Islamic Jihad said four of the men killed in the strikes were its fighters.
The latest attacks occurred as a high-level Israeli delegation was on a brief visit to Cairo on Saturday in an attempt to resume ceasefire negotiations in Gaza, Egyptian airport authority sources said.
The delegation returned to Israel hours later, Israeli media reported.
Chances of a breakthrough appear low as regional tensions have soared following the assassination of Hamas leader Ismail Haniyeh in Tehran on Wednesday, a day after an Israeli strike in Beirut killed Fuad Shukr, a senior military commander of the Lebanese armed group Hezbollah, an ally of Hamas.
Haniyeh's death was one in a series of assassinations of senior Hamas officials as the Gaza war nears its 11th month, and fueled concerns that the conflict in Gaza was spiraling into a wider war in the Middle East.
Both Hamas and Iran have accused Israel of carrying out Haniyeh's killing and have vowed to retaliate. Israel has neither claimed nor denied responsibility for the death.
