IDF reviewing airstrike after confirming an attack using ‘precision munitions’, which Gaza officials say killed eight children

An Israeli airstrike on the entrance of a school-turned-shelter in southern Gaza has killed at least 31 people as a stepped-up military offensive in the territory sent thousands fleeing in search of refuge.

The airstrike on Tuesday afternoon hit the tents of displaced families outside a school in the town of Abassan, east of Khan Younis. Officials at the nearby Nasser hospital said on Wednesday that 31 people had been killed, including eight children, and more than 50 wounded.

Footage broadcast by Al Jazeera showed children playing football in the school’s yard when a sudden boom shook the area, prompting shouts of “a strike, a strike!”

The Israeli military said it was reviewing reports that civilians were harmed. It said the incident occurred when it struck with “precise munition” a Hamas fighter who took part in the 7 October raid on Israel that precipitated the Israeli assault on Gaza.

The area hit was crowded at the time of the attack, according to witnesses who spoke to the BBC, one of whom reported that as many as 3,000 people were there at the time of the strike.

Further Israeli strikes in the early hours of Wednesday morning killed at least 20 Palestinians. Associated Press reported that 12 people had been killed in the Nuseirat refugee camp and eight at a home in Deir al-Balah, an area that is located within the “humanitarian safe zone” where Israel has told Palestinians to seek refuge as it conducts offensives in multiple parts of the Gaza Strip.

Last week, the the Israel Defence Forces (IDF) ordered a mass evacuation of parts of southern Gaza. Much of Khan Younis was destroyed in a long assault this year, but large numbers of Palestinians had moved back to escape another Israeli offensive in Gaza’s southernmost city, Rafah.

The militant group Hamas said the renewed Israeli campaign had killed more than 60 Palestinians across the territory on Tuesday alone.

This week, Israeli troops have also been waging a new ground assault in Gaza City in the north of the territory – its latest effort to battle Hamas militants regrouping in areas the army previously said had been largely cleared.

The Palestinian Red Crescent said its crews received dozens of humanitarian distress calls from Gaza City but were unable to help due to the intensity of the bombing there.

“The fighting has been intense,” Hakeem Abdel-Bar, who fled Gaza City’s Tuffah district to the home of relatives in another part of the city, told the Associated Press. Israeli warplanes and drones were “striking anything moving” and that tanks had moved into central districts, he said.

According to the United Nations’ humanitarian office, ‘‘only 13 of Gaza’s 36 hospitals are functioning, and those only partially’’.

“People have been observed fleeing in multiple directions, not knowing which way may be safest,” the agency said in a statement. It said the largest UN bakery in the city was forced to close, and that the fighting had blocked aid groups from accessing warehouses.

The Israeli military said that one overnight attack in Gaza City targeted Hamas and Islamic Jihad targets operating from inside the headquarters of the UN agency for Palestinians, Unrwa. The agency has not had control of the building since October. Israeli forces said in February they had found a Hamas tunnel underneath the headquarters.

The military said the militants were “operating inside Unrwa’s headquarters in the area and using it as a base to conduct attacks on IDF troops in the central Gaza Strip”.

It said that militants had been “eliminated” and “large amounts of weapons” found.

Unrwa had no immediate comment on the attack, but has said it has “no way to verify” claims that its facilities are being used by Hamas and its allies.

The last few days of airstrikes on the blockaded Palestinian territory are some of the fiercest since the war broke out. Hamas’s armed wing, the Izz ad-Din al-Qassam Brigades, described the fighting as “the most intense in months”.

The new fighting has unfolded as international mediators led by Egypt, Qatar and the US make a renewed effort to push through a proposed ceasefire deal. Talks are due to continue in Doha and Cairo this week, attended by the CIA director, William Burns, and the Mossad chief, David Barnea. “There is an agreement over many points,” a senior source told al-Qahera news on Tuesday.

However, Hamas has again accused Israel’s prime minister, Benjamin Netanyahu, of deliberately trying to thwart the truce talks.