The Hamas-run health ministry in Gaza has said at least 70 people were killed in an Israeli air strike at Al-Maghazi refugee camp in central Gaza.
Health ministry spokesman Ashraf al-Qudra said the strike had destroyed a densely populated residential block and that the death toll was likely to rise given the large number of families living the area.
The injured were taken to nearby Al-Aqsa Hospital.
The Israeli military has said that it is looking at reports of an incident in the Maghazi camp.
In a statement to the BBC, they said that despite the challenges posed by Hamas operating within civilian areas in Gaza, the military was committed to international law including taking feasible steps to minimise harm to civilians.