An Israeli inquiry into the killing of seven aid workers in an air strike in Gaza this week found serious errors and breaches of procedure by the military, with the result that two officers have been dismissed and senior commanders formally reprimanded.

The inquiry found Israeli forces mistakenly believed they were attacking Hamas gunmen when drone strikes hit the three vehicles of the World Central Kitchen aid group late on Monday night, and that standard procedures had been violated.

“The strike on the aid vehicles is a grave mistake stemming from a serious failure due to a mistaken identification, errors in decision-making, and an attack contrary to the Standard Operating Procedures,” the military said in a statement issued on Friday.

The killing of the seven aid workers, who included citizens of Britain, Australia and Poland, a dual U.S. Canadian national and a Palestinian colleague, triggered global outrage this week.