Palestinian security officials said an Israeli tank shell killed five children traveling in a car near the southern Gaza Strip town of Rafah on Thursday, but the IDF denied any army fire in the area. Hospital workers said the children were all siblings, under 16, from the Abu Matrok family. The driver of the car was also killed the security officials said. Earlier Thursday, the IDF took control of a few hills and open areas near Beit Lahiya in northern Gaza in an attempt to prevent Kassam rocket attacks on Israel. According to Israel Radio, a small force of tanks and other armored vehicles has been operating for the last few days a few hundred meters into Gaza on the Palestinian side of the security fence. Earlier Thursday, two Kassam rockets landed in the western Negev. One hit Sderot and one struck Kibbutz Nir Am. No one was wounded in either attack. Meanwhile, Defense Ministry Diplomatic-Military Bureau head Maj.-Gen. (res.) Amos Gilad said Thursday that Hamas's takeover of the Gaza Strip was a "dramatic development" that would affect the entire region. Gilad told Israel Radio that harsh action must be taken to prevent weapons from reaching the Strip, comparing arms to "air" for Hamas. Gilad also cautioned against Israel taking advantage of the recent upswing in violence to reenter Gaza. Such an operation was feasible, Gilad said, but other options should be considered. Gilad said that the "tempting" possibility of retaking Gaza raised many questions, such as how long the operation would last, who would command it, and what would happen after Israel decided to leave.