In pictures: Palestinians mourn in Khan Younis
Twenty-six members of the Abu Jame' family were killed by an Israeli air strike over a three-storey building in Khan Younis, late Sunday night.
Among the victims were 18 children and five women, two of them pregnant. The youngest child was a six-month old baby.
“There is no doubt about this case…dropping a bomb on a house full of civilians is a terrible war crime,” said Mahmoud Abu Rahma, Communications and International Relations Director of al-Mezan Centre for Human Rights.
"The house, located in the Bani Suhaila town, east of Khan Younis district in the south of the Gaza Strip, was inhabited by five families. It was attacked without prior warning and was completely destroyed in the attack," added Abu Rahma.
The new victims brought the Gaza death toll to 510 while the number of injured has passed 3,000. The death toll has since rised to more than 550.