At least seven people were reported killed and dozens injured Thursday in an explosion in the A-Shabura refugee camp in southern Gaza. Gaza rescue workers were transporting the injured to hospitals in Gaza City.

Hamas sources said that the explosion was due to a leftover IDF rocket which had been buried under rubble in the refugee camp. The rocket had apparently been fired during last summer’s Operation Protective Edge, as the IDF responded to the thousands of rockets fired on Israeli civilians by targeting areas where Hamas terrorists attacked Israel.

There was no confirmation from the IDF that the explosion was caused by material it fired at Gaza, either last year or more recently.