The other Qassam fell in the town's industrial area and damaged some equipment.
At least five Qassam rockets were fired at the western Negev on Friday morning. The rockets landed in open areas near the southern town of Sderot and south of Ashkelon.
There were no reports of injuries, but one of the rockets started a fire in a wheat field near Sderot.
The IDF operated in Gaza during the day, and a Hamas post was struck by an IAF plane in the central Strip.
On Thursday night, the IDF struck a number of buildings across the Gaza Strip, including a building used by Hamas near the home of Palestinian Prime Minister Ismail Haniyeh at the Shati refugee camp, as well as buildings in Khan Younis, Rafah and Jabalya. A money changer's office in the northern Strip was also attacked.
Meanwhile, it appears that Prime Minister Ehud Olmert has no intention of halting Israel's aerial offensive against Palestinian terror groups in the Gaza Strip despite calls by Palestinian President Mahmoud Abbas for a ceasefire.
"Israel will continue to operate against Hamas' terror. They will not control the situation, we will control the situation. We still haven't exhausted most of the targets that have been approved by the security cabinet," an aide to Olmert said Thursday evening.
Yael Branovsky contributed to the report