An explosion killed hundreds of people Tuesday at a hospital in Gaza City that was packed with people sheltering there, Gazan officials said, as Palestinians and Israelis blamed each other for a tragedy that inflamed the region just as U.S. President Joe Biden departed for Israel.

Hamas, the group that controls Gaza, said an Israeli airstrike had caused the blast at the Ahli Arab Hospital. Hours later, Israeli officials said that one of the rockets fired at Israel by Palestinian militants had failed shortly after launch, causing what could be the deadliest single incident of the 10-day-old war.

Photos and videos posted online and verified by The New York Times showed bloodied and battered bodies, flames, grieving witnesses and the blankets, backpacks and mattresses of the dead and wounded littering the area around them. Ali Jadallah, a Palestinian photojournalist in Gaza City, said he watched as victims arrived at another hospital, ferried there in any available vehicle, most of them dead. Many of the bodies were not intact, he said.