Aid charity World Central Kitchen on Friday demanded an independent commission to investigate the killings of its staff in an Israeli air strike in Gaza, saying the Israeli military could not credibly investigate its own "failure."

The aid workers were killed on Monday when their convoy was hit shortly after they oversaw the unloading of 100 tons of food aid brought to Gaza by sea.

"Without systemic change, there will be more military failures, more apologies and more grieving families," according to a statement published by WCK.

WCK founder and celebrity chef Jose Andres has said the Israeli attack had targeted his workers "systematically, car by car."

The U.S. and Israel's other allies called for an explanation into the incident, amid widespread condemnation.

Israel said on Friday that its inquiry into the incident had found serious errors and breaches of procedure by its military. Two senior officers have been dismissed and senior commanders formally reprimanded, it said. 

WCK said the action taken by Israel represented 'important steps ahead' but said it is also clear from the preliminary investigation that the Israeli military has deployed  deadly force without regard to its own protocols, chain of command and rules of engagement.

(Reporting by Ahmed Elimam and Clauda Tanios; Editing by Sharon Singleton)