A technical failure led to two Grad rockets striking Be'er Sheva on Sunday afternoon, Col. Tvika Haimovich, head of the IDF's active aerial defense system, told Haaretz.

One rocket hit a school that was empty at the time and the other struck a parked car in a residential neighborhood.

"Unfortunately, the incident in Be'er Sheva happened because of a technical failure in one of the system's components," Haimovich said. "It happened exactly when a rocket was in the air. We are doing everything to make sure there are no failures… but it would be irresponsible and unprofessional of me to say there is 100 percent protection."

The Iron Dome system has intercepted 40 rockets since Friday. More than 90 rockets have fallen in Israeli territory during that time. The Iron Dome is designed to intercept only rockets identified as heading toward populated areas.