The IDF was considering three possible scenarios for the attack on bus line 392 traveling Route 12 on Thursday.
One possible scenario was that terrorists, either from Egypt or possible from Gaza, fired from across the Egyptian border but did not cross into Israel.
A second option was that gunmen crossed into Israel, made the attack, and are still in Israel. This option prompted the IDF to set up checkpoints throughout the area.
The final scenario being considered was that the terrorists crossed into Israel, fired on Egged bus, and then fled back over the border near the Netafim crossing.
While the government has been working on completing a border barrier on the border along the Sinai peninsula, it has not been completed, and therefore large areas remain open and have been utilized for infiltration.