The Israeli army vowed Tuesday to investigate the air strike that killed seven aid workers in Gaza, saying "we will share our findings transparently". 

"We will be opening a probe to examine this serious incident further. This will help us reduce the risk of such an event from occurring again," Israeli army spokesman Rear Admiral Daniel Hagari said in a video statement. 

Citizens from Australia, Britain and Poland were among those working for celebrity chef Jose Andres' World Central Kitchen who were killed in an Israeli airstrike in central Gaza on Monday, the NGO said.

(With input from agencies)