Local sources reported that the Israeli warplanes bombed the Abu Hussein Elementary School, affiliated with the United Nations Relief and Works Agency for Palestine Refugees (UNRWA), which houses displaced people in Jabalia camp, north of the Gaza Strip.

The strike sparked fires in the displaced people's tents in the schoolyard, sources told WAFA news agency.

Fares Abu Hamza, head of the health ministry emergency unit in northern Gaza, said dozens of people were wounded.

The nearby Kamal Adwan Hospital was struggling to treat the casualties, he told AP. 

"Many women and children are in critical condition,” Abu Hamza added.

"Today's massacre is the 191st in the series of massacres committed by the occupation against displacement centres," the director of the Government Media Office in Gaza told Al Jazeera.

Hamas said in a statement that claims of fighters being present at the school were "nothing but lies," adding that this was "a systematic policy of the enemy to justify its crime."

The Israeli military claimed that the strike targeted dozens of Hamas and Islamic Jihad fighters who had gathered in the school.

Earlier on Thursday, at least three Palestinians were killed and others were injured when an Israeli strike bombed a tent at a school housing displaced people east of Deir Al-Balah City, central Gaza Strip.

Israel has killed at least 42,438 Palestinians and injured 99,246 since 7 October, the Palestinian health ministry said Thursday.