Mohammed Jakhbir leans back, braces himself, and then leaps off the roof of a Khan Yunis hospital building, flipping backwards before landing on the next roof over.
He whoops with delight at performing the dangerous feat, his favourite of the moves he practises with his team -- the first parkour group in the Gaza Strip.
Parkour, also known as free running, is an extreme sport that involves getting around or over urban obstacles as quickly as possible, using a combination of running, jumping, and gymnastic moves including rolls and vaults.
Practitioners leap from roof-to-roof, run up the side of buildings until they flip backwards, vault over park benches, or cartwheel along walls.
In Gaza, it's still a novelty, and as Jakhbir and four members of his 12-man crew demonstrate their skills in the grounds of the southern city's Nasser hospital, a crowd of patients and doctors look on, some filming with their cell phones.
"He's like Spiderman!" says one onlooker as 23-year-old Jakhbir runs up a wall, seemingly defying gravity as he scales the facade.
As the crowd grows, the team decides to move to a quieter spot. Their practice sessions are occasionally interrupted when onlookers call the police to complain, and they prefer to avoid having to make a run for it.
"When we first started practising, we could do it anywhere. But gradually we found people would complain and the police would come. It became a game, we'd practise until they arrived and then run away," Jakhbir laughs.
He's been practising parkour for seven years, ever since his friend Abdullah showed him a documentary called "Jump London".
It instantly appealed to them, and they started to learn more about the sport online.
"We would watch clips and try to imitate the moves that we saw. Gradually we started to make our own clips," he says.
"Now sometimes people even request that we make clips to show them certain moves. It's been a long journey for us, seven years, but now we have a real team."
Jihad Abu Sultan, 24, joined the team four years ago after seeing some of Jakhbir's clips on YouTube.
He had a background in both kickboxing and kung-fu, but saw something different in parkour.
"It uses physical strength more than any other sport... I was so impressed by it, especially the jumping involved," he says.
One of Abu Sultan's specialities is a move in which he flips his body in a full circle with one hand resting on a wall for him to pivot around.
He's also an accomplished tumbler, throwing himself along the ground in a series of handsprings, rolls and twists.
"Parkour teaches us to overcome obstacles," he says. "It makes me feel free, it makes me feel my body is strong, that I can overcome anything."
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But practising parkour in Gaza hasn't been easy.
At times they've had to shift practice locations because the areas have been targeted by Israeli air strikes. And both Abu Sultan and Jakhbir have battled disapproval from their families.
"At first, my parents forbade it," admits Abu Sultan.
"They tried to stop me, especially after I was injured, but they couldn't. It's in my blood."
Jakhbir's parents told him to stop practising parkour and find a job. He graduated with a degree in multimedia from Gaza's Islamic University, but has been largely unemployed ever since.
"They told me there was no future to it," he says with frustration.
"I want people to change their ideas about sports, all sports," he adds, raising his voice.
"They need to understand that sport is something very important. Athletes can raise Palestine's name throughout the world."
Jakhbir and other Gaza Parkour members were able to do just that earlier this year, when an Italian group called Unione Italiana Sport Per Tutti invited them to Italy.
"They were able to make our biggest dream come true, which was to get past the biggest obstacle of all -- the Israeli checkpoint -- and travel abroad," Jakhbir says.
The trip took them to Rome and four other Italian cities, where they met with other enthusiasts, showing off their skills and learning a few new ones.
"We talked to people about our lives in Gaza, that we're living under a siege, and in a continually tense situation. We face financial, social and political obstacles," Jakhbir recalls.
The parkour Gazans practise three times a week, mostly in a cemetery on the outskirts of Khan Yunis, which is quiet and usually empty.
In between modest headstones, they practise running and tumbling, and compete to see who can hold handstands the longest.
They've spray painted "Gaza Parkour forever" on some of the walls, but they acknowledge the team has an uncertain future.
Jakhbir and Abu Sultan say they'd like to continue parkour professionally, and are hoping to eventually win either local or international support that would allow them to commit to the sport full-time.
"Parkour teaches us we can overcome our problems even if we fail once or twice," says Jakhbir.
"We have to try and we can achieve our goals in life."