JERUSALEM — Israel issued a sweeping directive for all Palestinians to leave Gaza City on Wednesday, sowing mass confusion and fear among hundreds of thousands of affected residents.

       Leaflets dropped over Gaza City warned it was a “dangerous combat zone” and told civilians to flee south along two designated routes and toward shelters in central Gaza. Gazans and humanitarian groups have repeatedly warned there is no place in the territory safe from Israel’s nine-month-long air and ground assault that has devastated the enclave. Designated humanitarian zones are also crammed with those fleeing the fighting, leaving little room for new arrivals.