The U.N. has said Israel killed the workers. The video appears to contradict Israel’s version of events, which said the vehicles were “advancing suspiciously” without headlights or emergency signals.

A video, discovered on the cellphone of a paramedic who was found along with 14 other aid workers in a mass grave in Gaza in late March, shows that the ambulances and fire truck that they were traveling in were clearly marked and had their emergency signal lights on when Israeli troops hit them with a barrage of gunfire.