Israeli tank shellfire killed at least 51 Palestinians as they awaited aid in Khan Younis in the Gaza Strip, the territory's health ministry said.

A spokesperson for the Israeli Defense Force says it the organisation is aware of the incident and is investigating. It's the latest in a string of deadly incidents at Gaza aid sites.

Palestinians say Israeli forces opened fire on people trying to access a U.S.-backed group's aid distribution hub in Gaza, in the deadliest of such incidents reported to date.