Israeli strikes in central Gaza killed at least 35 people Sunday, hospital officials said, as fighting raged across the tiny enclave a day after Israel’s prime minister said the war will continue for “many more months,” resisting international calls for a cease-fire.

The military said Israeli forces were operating in Gaza’s second-largest city, Khan Younis, and residents reported strikes in the central region, the latest focus of the nearly three-month air-and-ground war that has raised fears of a regional conflagration.