Image caption Mohammed Eesa, 13, Parwana, 8, Khorshid, 14, and Nawab, 17 were all killed in the suicide bomb attack

In a video filmed in June, 14-year-old Khorshid tips her skateboard off the high edge of a quarter-pipe, at Kabul's indoor skatepark.

She appears fearless - and she was, say her friends, until she was killed by a Taliban suicide bomber last weekend.

A bright pink blur, she launches at speed over the ramps and berms at the skateboard park, called Skateistan.

Benafsha Tasmim works at the park, which provides a refuge for Kabul's poorest, an escape from the hardships of the city's streets.

"When I'm skateboarding, I feel like I'm flying and I feel very proud and confident, it gives me confidence," she said.

The project encourages children to get back to school. For the moment, they are mourning the friends they lost in the bombing.

Skateistan Begun in Kabul in 2007 by Australian Oliver Percovich

Initially had 10 skateboards and offered daily practice sessions and bootcamps

Funding provided by Danish and Norwegian embassies

Land for skatepark donated by Afghan Olympic Committee

400 children are members, 40% of them girls

Holds separate classes for girls and boys so girls can take part Skateistan mourns its bright sparks

"Khorshid really had a passion for her future, and she transferred this passion to other students also, that was so special about Khorshid," Benafsha continued. "Her passion was not just for herself, but for everyone."

Khorshid was killed alongside her eight-year-old sister, Parwana, and two other skaters from her gang - Nawab, who was 17, and 13-year-old Mohammed Eesa. Assad, Khorshid's cousin, also died.

They were street children, selling trinkets to foreigners in Kabul's embassy district, when the Taliban bomber struck.

The streets there are quiet now. A child walks past, but is accompanied by his elder brother. People are wary here.

Across from the pock-marked wall, where the explosion went off, is a tree with four brightly coloured scarves wrapped around its trunk.

At its base, there is a note, written in English. It reads: "We've tied these scarves to show how much we loved the children, and how brave they are."

Newly cautious

Around the corner and outside the many security checkpoints, Ashraf and his brother, 11 and nine years old respectively, collect tin cans to sell to support their families.

Media playback is unsupported on your device Media caption Footage shows some of those who died skateboarding at a community project

Cheeky and persistent, their charm means they will usually leave any foreigner laughing, and a few dollars short. These days, Ashraf is more cautious.

He said: "Our family tells us to be careful when you're on the street - when you see a crowd of people, run away and come home.

"When the Wazir Akber Khan attack happened I was on this street. I was so scared I ran away. A policeman gave me and my friend a lift to our houses."

Afghanistan has to be about the worse place in the world to be a child. Five children are killed or seriously wounded here every day.

The further horror of last weekend's attack is that it was carried out by child - a teenage boy - with a Taliban bomb in his backpack.

Peter Crowley, head of Unicef in Afghanistan, said: "We have confirmed reports up to the end of June of five children having been used in attacks by anti-government elements, and the figure for last year was 11. It's an appalling thing. There are official statements by the Taliban that proscribe this, but nevertheless, it does continue to happen."

At Skateistan, the lessons continue with trips and falls, bumps and bruises. But the kids are quick to get back on their feet.

The killing of children brings the brutality of war into sharp focus.

Here, they simply miss their exceptional friends, whose sudden death makes no sense whatsoever.