An Israeli air attack on a school housing displaced Palestinians in southern Gaza has killed at least 30 people in the fourth such attack in as many days.

The attack in the town of Abbasan, east of Khan Younis, hit the entrance of al-Awdah school, wounding at least 53 people. Palestinian medics said most of the victims were women and children.

The Israeli military said it carried out the strike on Tuesday as it was targeting a “terrorist from Hamas’s military wing” near the school. It acknowledged carrying out three other strikes since Saturday on Gaza schools being used as shelters.

“Since the war began, two-thirds of UNRWA schools in Gaza have been hit, some were bombed out, many severely damaged,” said Philippe Lazzarini, head of the United Nations agency for Palestinian refugees (UNRWA).

“Schools have gone from safe places of education and hope for children to overcrowded shelters and often ending up a place of death & misery,” he posted on X.

On Saturday, an Israeli strike hit al-Jawni school in Nuseirat, in the centre of the enclave, killing 16 people, according to Gaza’s Ministry of Health. UNRWA said 2,000 people were sheltering there at the time.

The following day, a strike on the Holy Family school in Gaza City killed four people, according to Gaza’s civil defence agency.

The Latin Patriarchate, owners of the school, said hundreds of people had packed the grounds at the time.

Another UNRWA-run school in Nuseirat was hit on Monday. A local hospital said several people were taken in for treatment.

“The blatant disregard of international humanitarian law cannot become the new normal,” Lazzarini said, calling for an immediate ceasefire.

Hamas has warned that the stepped-up Israeli offensive could jeopardise mediated ceasefire talks, with another round taking place on Wednesday in Qatar.