Israeli air strikes in central Gaza killed at least 18 people, including children, a day after 33 were killed at a United Nations-run school sheltering displaced Palestinian families, health officials said.

Overnight strikes were recorded at the Nuseirat and Maghazi refugee camps and the towns of Deir al-Balah and Zawaiyda.

Four children and one woman were among those killed as well as the mayor of the Nuseirat municipality, according to hospital records.

Meanwhile, Israel’s army said it is continuing operations in parts of Central Gaza. It said its troops had killed dozens of militants, located tunnel shafts and destroyed infrastructure in the area.

The strikes came a day after at least 33 people were killed at a UN-run school in the Nuseirat refugee camp which Israel said was being used as a Hamas compound, without providing evidence.

International pressure has been mounting on Israel to limit civilian bloodshed in its war against Hamas.

Spain’s foreign minister has announced it would ask a United Nations court for permission to join South Africa’s case accusing Israel of genocide in Gaza. Israel strongly denies the accusation.

More than 36,000 Palestinians have been killed by eight months of Israeli bombardments and ground offensives in Gaza, according to the health ministry, which does not distinguish between combatants and civilians.

The war has largely cut off the flow of food, medicine and other supplies to Palestinians who are facing widespread hunger.

United Nations agencies say over one million in Gaza could experience the highest level of starvation by mid-July.

Israel launched the war after Hamas’ October 7 attack, in which militants stormed into southern Israel, killed some 1,200 people – mostly civilians – and abducted about 250.

Around 80 hostages captured on October 7 are believed to still be alive in Gaza, alongside the remains of 43 others.