"A report by US-based group Human Rights Watch says the deaths [on Gaza beach] were likely to have been caused by Israeli shelling.
An expert working for the group said the Palestinians' injuries were not consistent with an explosion taking place beneath them.
"All of the evidence is pointing to a 155mm shell as having killed and injured the Palestinians here on the beach," Mark Garlasco said.
"My assessment [is] that it's likely that this was incoming artillery fire that landed on the beach and was fired by the Israelis from the north of Gaza."
From the Guardian:
"...a former Pentagon offical sent by the New York-based Human Rights Watch to investigate the death of the family has concluded that there is little doubt they were killed by an Israeli shell. "All the evidence points to the fact that it couldn't have been a mine," said Marc Garlasco, a former Pentagon expert on battlefields who led the US military's battle damage assessment team in Kosovo and worked for its intelligence wing, the Defense Intelligence Agency.
"You have the crater size, the shrapnel, the types of injuries, their location on the bodies. That all points to a shell dropping from the sky not explosives under the sand."
"The 155mm shell is what Israel uses in the howitzers that regularly shell northern Gaza," he said.
"The Israelis have been postulating that it's a land mine. I've been to hospital and seen the injuries. The doctors say they are primarily to the head and torso. That is consistent with a shell exploding above the ground not a mine under it." Palestinian doctors agreed.
Mr Garlasco said the crater where the family was killed closely resembles others scattered the length of the beach caused by Israeli shells. Each is lined with a white power left by the explosion, including the one where the family died.
A crucial weakness in the army's version is its inability to account for the sixth shell in the barrage that hit the beach. The Palestinians and Mr Garlasco say it would be a remarkable coincidence for the army to drop five shells in the area and within minutes for a Hamas land mine to have exploded just 120 metres away.
"To say you have five or six rounds in an area and coincidentally there's a land mine next to it and it goes off at the same time is asking a lot," he said."