President Joe Biden said on Thursday that he believes negotiations for a possible truce between Israel and Hamas will be complicated by an incident where Gaza officials say Israeli troops killed more than 100 starving Palestinians trying to access aid.

Earlier that day, Israeli forces in Gaza City fired at a crowd of Palestinians after the enclaves northern region received its first major aid delivery in a month. Hundreds of Palestinian civilians, who are being starved by the lack of aid , began pulling flour and canned goods off the trucks when witnesses said troops began shooting at them.

Medics found dozens or hundreds lying on the ground at the scene, Kamal Adwan Hospital official Fares Afana told The Associated Press . Because there were so many bodies, Afana said some of the victims had to be wheeled to the hospital in carts pulled by horses and donkeys instead of ambulances. Video taken by a Gaza journalist shows medics assisting a single donkey carrying a cart that has a pile of bodies stacked on top of each other.

The Gaza Health Ministry, which described the shooting as a massacre, said more than 100 Palestinians were killed and 760 were wounded. The casualties resulted in the Palestinian death toll surpassing 30,000 , with another almost 70,500 wounded, according to health officials.