Salih al-Masri, a skinny nine-year-old in a red martial arts uniform, grits his teeth as he stands barefoot on shards of broken glass and recalls his family's plight during the war in Gaza.
"This sport makes me strong so I can defend myself, my family and my country from the Jews," he says, without betraying the slightest wince of pain.
"We ran away from our home during the war because we were afraid of the shelling," he adds. "But after we returned I started coming here every day to train. Now I'm strong, and I'm not afraid of anyone."
Haunted by what they saw during the massive Israeli assault on the Gaza Strip at the turn of the year, growing numbers of children are flocking to martial arts classes across the devastated Palestinian coastal territory.
Private clubs offering kung fu and karate lessons have attracted scores of new students in the wake of the fighting, a phenomenon child psychologists attribute to widespread mental trauma.
On a recent summer day several of the younger students at a club in the northern town of Beit Lahiya gathered to watch in awe as Salih al-Sawalja, 15, lay on a bed of nails with two other boys standing on his chest.
"No one will be able to mess with us after we become kung fu masters," a wide-eyed Nashaat Abu Harbid, a nine-year-old, says. "Everyone will be afraid of us."
As Sawalja moves on to the next exhibition, where he will walk barefoot over the upturned blades of several large knives, he explains that kung fu increases his self-confidence and allows him to "protect myself from anything."
Helmi Matar, a coach at the Beit Lahiya club, says interest in the martial arts has grown in the wake of the war, which killed more than 1,400 Palestinians and left vast swathes of the impoverished enclave in ruins.
Releasing pent-up energy
"Interest in the sport grew exponentially after the war because people wanted a distraction and for their kids to release pent-up energy," he says.
A spokesman for Gaza's kung fu and karate union confirmed that attendance at the classes has doubled since the war.
Child psychologists fear that the increased interest stems from the trauma children suffered during the three weeks of near-continual land, sea and air strikes.
"Children internalize a huge amount of violence in war and they are not able to express it, especially when they feel that no one in their family can protect them," says Iyad Sarraj, a psychiatrist and director of the Gaza Community Mental Health Program.
"Violence begets violence. The children try to release this built-up energy during sports. They choose violence because it fits with their situation and to boost their sense of power and security."
Cycle of violence
Osama Darabih, a lean teenager with a strip of black cloth wrapped around his forehead, has been studying kung fu for three years but says he started coming every day after the war.
"These sports are dangerous and there have been injuries and accidents during training," he says as he waits his turn to spar. "But we train well because we love it. It relaxes us and releases our tensions."
More than half of Gaza's 1.4 million residents are under the age of 18, and psychologists fear the coming generation will be snared by the cycle of violence that has afflicted the territory since the 2000 Palestinian uprising.
Samir Zaqut, a psychologist who works with Sarraj, says the children are drawn to violent activities by what they have experienced.
"When these children put their necks or their heads on broken glass or lie on nails they are in danger. But people who face repeated traumas like to take risks and are drawn to danger."
Zaqut fears that by encouraging interest in such activities, the club owners may be feeding into the violence that has convulsed the territory in recent years and scarred its young people.