Israel's military said buildings were destroyed because of military "operational needs".
The Israeli Defense Forces said they operated in accordance with international law during the conflict.
However, the use of mines to destroy homes contradicted this claim, the head of the Amnesty International fact-finding mission to southern Israel and Gaza, Donatella Rovera, has argued.
Israeli troops had to leave their vehicles to plant the mines, indicating that they faced no danger and that there was no military or operational justification, she said.
Breaking the Silence, an Israeli group that gathers and circulates the testimonies of Israeli soldiers, has also told the BBC News website that its findings from the Gaza war suggested many demolitions had been carried out when there was no immediate threat.
"From the testimonies that we've gathered, lots of demolitions - buildings demolished either by bulldozers or explosives - were done after the area was under Israeli control," said Yehuda Shaul, one of the group's members....