Five bulldozers from Israel's Kissufim military base pushed some 150 meters into the cities of Rafah and Khan Younis, according to eyewitnesses.
The bulldozers leveled a large tract of agricultural land before leaving the area, witnesses added.
There was no comment from the Israeli army.
On August 26, Israeli and Palestinian negotiators signed a cease-fire deal in Cairo, ending a seven-week Israeli military onslaught on the Gaza Strip.
The Israeli offensive, which began on July 7, left 2,160 Palestinians dead – the vast majority of them civilians – and more than 11,000 injured.