Two years ago, Gaza’s largest city was sprawling with life. Classrooms brimmed with schoolchildren, markets were full of shoppers and beachside cafes offered respite for those escaping the stresses of a besieged enclave.

Israeli planes and tanks pounded the eastern and northern outskirts of Gaza City overnight Saturday to Sunday, destroying buildings and homes, residents said, as Israeli leaders vowed to press on with a planned offensive on the city.