Palestinian witnesses said Wednesday that an angry crowd of people in the Gaza Strip stormed a border crossing with Egypt and was throwing rocks at Egyptian troops.
The witnesses said Egypt was repelling the crowd with water cannons, and that no-one had made it across the border.
The Palestinians were upset that they are not being allowed to cross into Egypt. The Egyptians had promised to open the Rafah crossing on Tuesday, but only a small number of Palestinians were allowed through.
Egypt has kept the crossing sealed since Hamas militants seized control of Gaza more than a year ago.
Rafah is the main gateway for Palestinians to the outside world. In January, Hamas militants blew open the border, allowing thousands of people to cross through until it was resealed about two weeks later.