Gaza City, Sept. 24 -- Israeli air and ground strikes killed at least 84 Palestinians in the Gaza Strip on Wednesday as the army pressed a destructive push deeper into Gaza City, a campaign denounced by United Nations officials for tactics that have driven tens of thousands to flee again and again with no safe place to go. The deadliest blasts were reported in the city's northern districts and along the coastal road south of Wadi Gaza, where families trying to move out of the combat zones were forced to run under the howl of drones and the rumble of tanks.

Local rescue teams described a morning and afternoon of unbroken sirens, smoke, and frantic calls from neighborhoods that had already been hit several times since the renewed offensive...