Israel pressed ahead with its Gaza offensive on Sunday after a series of shootings, including of three hostages who were shirtless and waving a white flag, raised questions about its conduct in a 10-week-old war that has brought unprecedented death and destruction to the coastal enclave.

Gaza remained under a communications blackout for a fourth straight day — the longest of several outages over the course of the war, which aid groups say complicate rescue efforts after bombings and make it even more difficult to monitor the war’s toll on civilians.