Palestinian health officials say Israeli warplanes struck a refugee camp in the central Gaza Strip, killing at least 40 people and wounding dozens. Sunday’s strike came as Israel vowed to press on with its offensive to crush the territory’s Hamas rulers, despite U.S. appeals for a pause in fighting to get aid to civilians.

Arafat Abu Mashaia, who lives in the camp, said the Israeli airstrike flattened several multi-story homes where people forced out of other parts of Gaza were sheltering.

“It was a true massacre,” he said early Sunday while standing on the wreckage of destroyed homes. “All here are peaceful people. I challenge anyone who says there were resistance (fighters) here.”