Israeli fighter jets have struck two refugee camps in the Gaza Strip, killing at least 53 people and wounding dozens, according to health officials in the besieged enclave.

The attacks on Sunday came as Israel said it would press on with its offensive against Hamas, despite international appeals for a ceasefire or a “humanitarian pause”.

Air raids hit the Maghazi refugee camp in central Gaza overnight, killing at least 40 people and wounding 34 others, the Ministry of Health said.

Arafat Abu Mashaia, who lives in the camp, said the air raids flattened several multistorey residential buildings where people forced out of other parts of Gaza were sheltering.

“It was a true massacre,” he said, standing on the wreckage. “All here are peaceful people. I challenge anyone who says there were resistance [fighters] here.”

The camp, a built-up residential area, is located in the evacuation zone where Israel’s military had urged Palestinian civilians to seek refuge as it focused its military offensive on the north.

Another air attack hit a house near a school at the Bureji refugee camp in central Gaza on Sunday, and staff at al-Aqsa Hospital said at least 13 people were killed. The camp is home to an estimated 46,000 people and was struck on Thursday as well.