Israeli forces shelled a United Nations-run school housing Palestinian refugees Tuesday, killing at least 15 people, the Gaza Health Ministry said Thursday. 

Gaza health official Ashraf al-Kidra told the Associated Press that at least 150 people have been injured. The school, located in Beit Hanoun, a town in the northern Gaza Strip, was housing hundreds of mostly women and children when the clash began. Reporters have descended onto the scene to tweet observations:

Chris Gunness, the spokesman for the UN Relief and Works Agency, which ran the school and various shelters for refugees, tweeted that the shelter had been targeted by the Israeli army, and that the UNRWA attempted to help civilians leave:

However, Israel Defense Forces Spokesman Peter Lerner says the UN had been warned to vacate the shelter in advance:

This incident comes as the fourth UN facility caught in the fighting between Israel and Palestinian militants in Gaza, which is ruled by the Islamic militant group Hamas, since the Israeli operation began July 8. More than 140,000 Palestinians have fled their homes for buildings run by the UNRWA.

Reuters