On Saturday, a group of international and Palestinian rights groups and aid agencies urged an immediate ceasefire in Gaza, noting the high number of children killed in Israeli raids.
"So far, more children have been killed by Israeli fire than Palestinian militants," said a statement from the groups, including War Child and Defence for Children International.
On Saturday, the UN children's agency, UNICEF, said children made up more than one third of civilian casualties in the Israeli offensive on Gaza.
"From July 8th, until 4:00am on July 19, at least 73 Palestinian children have been reported killed as a result of airstrikes and shelling Israel aerial, naval and ground forces," UNICEF's Catherine Weibel said.
She said the children included 53 boys and 20 girls under the age of 18 years old.
"The youngest was reportedly three months old," she said.
More than half of the children killed are under the age of 12.
In one incident, ten-year-old Afnan Shuheiber was playing on a Gaza City rooftop with her cousins when she became one of at least 73 children killed by Israeli fire in the Gaza Strip.
Afnan, known as Fulla by her family, was among them, was killed on Thursday afternoon along with her cousins, Jihad and Wissam, in Gaza City's Sabra district.
Neighbours said the children were taking advantage of the relative lull in the violence that afternoon, going to the roof to relax after days of being cooped up at home.
Weibel said the number of children among the dead in Gaza was of "deep concern" to UNICEF.
"Children should be protected from the violence, and they should not be the victims of a conflict for which they have no responsibility," she said.
She also raised concerns about the long-term effects of the violence on Gaza's children, many of whom are now living through their third war in less than six years.
"You have children who are going to be scarred for life because of what they are seeing," said Weibel.
Even before the war, some 60,000 children in Gaza were in need of psychosocial support, she said, and the number is expected to soar after this conflict.
The potential for such problems is evident every day in Gaza -- wide-eyed children seeing their relatives and friends buried after shelling.
RA/SHI