Israel continued pummeling Hamas targets in Gaza as Palestinian missiles struck deeper into Israel. So far 18 Gazans have been killed and more than 65 wounded since the strikes began in response to a Hamas attack on an Israeli school bus Thursday. It's not clear why Hamas decided to attack after largely observing the ceasefire that followed the Gaza war in 2008-2009. Hamas said the strikes were in retaliation for the killing of three fighters in an airstrike earlier in the week, and that they would be forced to escalate violence if Israel continues with its strikes. Hamas missiles have reached the towns of Ashdod, Ashkelon, and Beersheba, but no Israelis were wounded, and several of the missiles were intercepted by the country's new missile defense system, Iron Dome.