BEIT HANOUN, Gaza Strip - Israeli ground troops, tanks and armored vehicles advanced on two northern Gaza towns Wednesday in pursuit of Palestinian rocket squads, besieging a well-known Hamas lawmaker's house and engaging militants in ferocious clashes, Palestinian officials said. Militants, undeterred by Israel's military might, pressed ahead with their rocket attacks on southern Israel. A 22-year-old Palestinian affiliated with the military wing of the ruling Hamas party was shot and killed while launching a projectile, the group said. Earlier in the day, a rocket hit an Israeli school just before pupils arrived. The surge in violence coincided with a...