US-based World Central Kitchen -- founded by Spanish-American celebrity chef Jose Andres -- said a "targeted attack" by Israeli forces on Monday had killed seven aid workers.

The group included 43-year-old Australian national Lalzawmi "Zomi" Frankcom, as well as British, Palestinian, Polish and US-Canadian employees.

After being briefed by Israeli authorities, Australia had "made clear that we have not yet received sufficient information to satisfy our expectations" about Frankcom's death, Wong told reporters.

Israeli Prime Minister Benjamin Netanyahu later admitted that his military had "unintentionally" killed the group -- who had helped feed communities affected by conflict and disaster -- in an air strike.

"We expect full accountability for her death and for the World Central Kitchen colleagues who also perished with her," Wong said.

"We believe these deaths are utterly inexcusable and clear practical action is needed to ensure these tragedies are never repeated."

Wong acknowledged that Israel has confirmed that two individuals involved in the air strike have since been "stood down".

"We reiterate that appropriate action must be taken against the individuals who are responsible for these tragic accidents," she added.

Australia's prime minister Anthony Albanese rang his Israeli counterpart Netanyahu on Wednesday to express his "anger" over the tragedy, which happened Tuesday.

Television clips and posts on social media painted a picture of Frankcom as an intrepid aid worker who did not shy away from the frontlines of disaster.

In September last year, she travelled to Morocco to help World Central Kitchen relief efforts in the wake of a devastating earthquake.

World Central Kitchen is one of two NGOs spearheading efforts to deliver aid to Gaza by boat from Cyprus.