Tens of thousands of Palestinians have poured into Egypt from Gaza, after militants blew holes in the border wall.
Egypt had been under pressure to let Palestinians cross since Israel sealed Gaza's crossing points last week.
Some reports say two-thirds of the border wall were destroyed following explosions during the night.
Many Palestinians have taken the opportunity to stock up food, fuel and other supplies.
They walked unhindered over the toppled metal plates that made up the wall.
The militant group Hamas, which controls Gaza, had urged Egypt to open its border.
Egyptian border guards have so far taken no action to stop people streaming across, eyewitnesses said.