At least three sons and three grandchildren of Hamas leader Ismail Haniyeh were killed in an Israeli air attack on a Gaza refugee camp, Al Jazeera reports.

Haniyeh told Al Jazeera that his children were visiting relatives for Eidul Fitr at the Shati refugee camp in northern Gaza when they were targeted.

The Hamas chief decried what he described as Israel’s brutality, but stressed that Palestinian leaders will not back down if their families and homes are targeted.

“There is no doubt that this criminal enemy is driven by the spirit of revenge and the spirit of murder and bloodshed, and it does not observe any standards or laws,” Haniyeh said, adding that 60 members of his family have been killed since the start of the conflict.

“We’ve seen it violate everything on the land of Gaza. There is a war of ethnic cleansing and genocide. There is mass displacement.”