There were no injuries.
The Rafah crossing is where tens of thousands of Palestinians broke through into Egypt last month to seek relief from the blockade imposed by Israel.
Egypt has since resealed the border but it has been holding talks with the Palestinian Islamist movement Hamas, which controls Gaza, on how the border might reopen.
The security sources said that at the time the projectile landed on Sunday Israeli forces were carrying out an attack in the Palestinian side of the town.
A group of experts is examining the impact site to find out what the projectile was and where it came from, they added.
Güncelleme Tarihi: 17 Şubat 2008, 14:36