For most people, childhood is a time of leisure and learning.
For the children of the IS-held Syrian city of Raqqa, it is anything but that.
Those who have escaped the intense fighting inside Raqqa between IS, or ISIS, and United States-backed Syrian rebels are haunted by bombings and beheadings.
The charity Save the Children says the psychological scars could take years, even decades, to heal.
A woman named Deena and her husband live in Raqqa with their two sons, one four years old, the other seven months old.
Their adopted daughter lived in Idlib before her family died in an air strike, and Deena's brother was also killed in an air strike.
Now, she looks after her orphaned niece.
"The orphan children of Syria don't have anything or anyone. No brother, no mother, no sister, no father. Sometimes, she sees a picture of her father and she starts crying. He was my oldest brother. I also cry when I see his picture. Children get scared when they see an aeroplane, even if it isn't striking. They wake up from sleep if they hear the sound. 'The aeroplane is here! Hide! Hide!'"
Thirteen-year-old Raashida says the children in Raqqa live a life of unthinkable brutality, witnessing executions and explosions at close quarters.
"One day, they beheaded people and left their bodies on the ground. When I saw this, I couldn't handle it. I wanted to sleep, but I couldn't when I remembered what I saw. I would stay awake, or have nightmares from how scared I was. Children's lives have passed them by. They haven't experienced childhood. They haven't seen toys or parks. They only sit at home terrified of ISIS. They don't want to go outside the house because they're so scared."
Including children, an estimated 20,000 civilians are trapped inside Raqqa.
Earlier this week, United Nations humanitarian adviser Jan Egeland called for a humanitarian pause to let residents escape.
"The casualties, civilian casualties, are large. And there seems to be no real escape for these civilians. Now is the time to think of possibilities, pauses or otherwise, that might facilitate the escape of civilians, knowing that Islamic State fighters are doing their absolute best to use them as human shields. I cannot think of a worst place on earth now than in these five neighbourhoods."
The United Nations is assessing the outcome of talks held this week in Riyadh between three Syrian opposition groups, who failed to unite.
Peace talks are expected to be held in Geneva next month.
