Israeli airstrikes killed at least 31 people in the Gaza Strip on Sunday, Palestinian medics said, with nearly half of the deaths in northern areas where the army has waged a month-long campaign it says is aimed at preventing Hamas from regrouping, Reuters reported.

Palestinians said the new aerial and ground offensives and forced evacuations were “ethnic cleansing” aimed at emptying two northern Gaza towns and a refugee camp of their population in order to create buffer zones. Israel denies this, saying it is fighting Hamas militants who launch attacks from there.

Medics said at least 13 Palestinians were killed in separate attacks on houses in Beit Lahiya town and Jabalia, the largest of the enclave’s eight historic camps and the focus of the army’s new offensive.

The rest were killed in separate Israeli airstrikes in Gaza City and in southern areas, including one in Khan Younis, which health officials said had killed eight people, including four children.

Later on Sunday, health officials at the Kamal Adwan Hospital near Beit Lahiya said the facility came under Israeli tank fire and that one child hospitalized at the hospital was critically wounded.

Hussam Abu Safiya, the hospital’s director said the incident took place after a delegation from the World Health Organization visited the facility and evacuated some patients.

He said while evacuating the wounded was important, it was more important to dispatch specialized medical teams to north Gaza hospitals that have become overwhelmed by the number of casualties.

Abu Safiya said the tank fire hit the water supplies, the courtyard, and the neonatal intensive care unit.

COGAT, the Israeli army’s Palestinian civilian affairs agency, said the explosion resulted from an explosive device planted by Palestinian militants and not an Israeli attack.

“The terrorist organizations continue to exploit civilian infrastructure, medical facilities, and international aid organizations for their terror activities,” a COGAT statement said late on Sunday.

Hamas has repeatedly denied using civilian facilities such as hospitals, schools, and mosques, for military purposes.

On Saturday, the Israeli military sent a new army division to Jabalia to join two other operating battalions, a statement said. It said hundreds of Palestinian militants have been killed in the “battles” since the raid began on Oct. 5, read the report.

Meanwhile, COGAT said it facilitated the launch of the second round of a polio vaccination campaign in northern Gaza on Saturday and that 58,604 children have received a dose.

The Gaza health ministry said Israel’s military offensive in northern Gaza was stopping them from vaccinating thousands of children in Jabalia, Beit Lahiya, and Beit Hanoun.

It said one clinic had come under Israeli fire while parents brought their children for the anti-polio dose on Saturday and that four children had been injured.

The head of the World Health Organization said in a statement the clinic incident took place despite a humanitarian pause agreed upon by the two warring parties, Israel and Hamas, to allow the vaccination campaign.

“A @WHO team was at the site just before. This attack, during a humanitarian pause, jeopardises the sanctity of health protection for children and may deter parents from bringing their children for vaccination,” Director-General Tedros Adhanom Ghebreyesus said in a post on X on Saturday.

“These vital humanitarian-area-specific pauses must be absolutely respected. Ceasefire!” he said.

The Israeli military, which had no immediate comment on Tedros’ remarks, said it was checking the report about the clinic.

A larger ceasefire that would end the war and see the release of Israeli and foreign hostages held captive in Gaza as well as Palestinians jailed by Israel remains remote due to disagreements between Hamas and Israel.

Hamas wants an agreement to end the war permanently, refusing recent offers for temporary truces, while Israeli Prime Minister Benjamin Netanyahu says war can only end when Hamas is eradicated, Reuters reported.

The war erupted after Hamas-led militants attacked Israel on Oct. 7, 2023, killing some 1,200 people and taking 251 hostages back to Gaza, according to Israeli tallies.

Israel’s retaliatory offensives have killed more than 43,300 Palestinians and reduced most of Gaza to rubble.