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.

A CNN investigation into a deadly incident near an aid distribution site in southern Gaza on Sunday points to the Israeli military opening fire on crowds of Palestinians as they tried to make their way to the fenced enclosure to get food.

Palestinian health officials and witnesses say Israeli forces fired on people as they headed toward an aid distribution site on Tuesday, killing at least 27, in the third such shooting in three days.