Russian teenager Chermen has his own assessment of why he survived the attack on School Number One in Beslan in which 326 people, 186 of them children, died.

“God wanted to save everyone but He saved only those who had the highest purpose in life. So I know that when I grow up I will become someone great,” he said.

On the morning of 1 September 2004 Chermen was just eight years old and running late for the Day of Knowledge, as the traditional start of the school year is known in Russia.

Chermen made it to the commencement celebrations in time, but in doing so was in the school when a group of Chechen gunmen attacked, taking more than 1,000 people hostage.

The militants herded the hostages into the school gym, and there they held them for three days.

Inside the sweltering gym the terrorists refused to give hostages food or water, forcing them to take drastic measures.

“I drank pee. It was tasteless. I also found a piece of pear skin on a floor. It was really good,” Chermen told me when we first met. “But mostly I slept.”

At one point he was woken by the sound of an explosion inside the gym. Chermen saw how one of the militants had blown himself up with a grenade attached to his body:

“A terrorist grenade was hit by a bullet. He blew up and his brains hit me in the face. It was horrible. It was fatty and slippery,” he said.

The explosion triggered a fierce gun battle between the hostage takers and the Russian Special Forces, who stormed the school in a desperate rescue bid.

Chermen’s story was one of many I listened to shortly after the attack.

I had arrived in the town in November 2004 to make a BBC documentary and I stayed for weeks, forging close relationships with the youngsters and their families.

In total I spoke to 140 child survivors during that time. Their accounts varied only in the gory details and the amount of horror they had lived through.

I returned to Beslan in May 2009, passing on the drive from the airport to the town centre the cemetery which had been built to bury the attack victims in row upon tidy row.

Five years ago there were just wooden crosses marking the graves, most of them bearing a photo of a slain child and covered in toys.

The toys are still there, but now there are also headstones, all built from the same copper-coloured marble. By the entrance an imposing new statue of three gigantic angels holding baby ones on their stretched hands dominates the site.

“They named the cemetery a City of Angels because all the children, all the people buried here were angels,” 14-year-old Lana told me. “They were all beautiful and kind. But it was their destiny.”

Lana, goes to the cemetery to visit the grave of her four-year-old brother. Her father, unable to cope with the loss of his only son, died shortly after the attack from heart failure.

Like so many of the children I met again, Lana is still trying to overcome a torment of her memories of the siege, which bring out emotions unfamiliar to most her age.

“I can’t forget how the terrorists were killing children, mothers and fathers right in front of us,” she said. “They caused us so much pain. I am so angry with them I could kill them. They took the most precious things in my life, my brother and my father.”

Laima, another survivor who is also now 14, has made a ritual of her visits to the grave of her best friend who was killed.

“I go to visit Zayka at the cemetery. I sit by her grave and talk to her. I ask her ‘how is life over there? How are you doing?’ I believe she is still near me. For me she isn’t dead.”

But others, like Christina, are still troubled by thoughts of those who died.

“I am scared of my dead friends. They come to me in my dreams. They have changed. They are dressed in black. They are angry and say ‘Why us? We wanted to live too!'”

And Chermen said that he never goes to the cemetery “because I am simply afraid to flood Beslan with my tears”.

Today life in Beslan shows some signs of normality. There are new playgrounds and attractions for children built with some of the £20m in donations which flooded in during the months following the siege.

And in the last five years Beslan has enjoyed a baby boom, including 50 children born into families affected by the attack.

For many these new arrivals have brought hope and a renewed sense of purpose.

Diana, who was eight when she was caught up in the attack, says of her little sister Karina, born two years after the siege: “She makes me forget about what happened. I taught her how to ride a bike. The first word she said was Diana.”

Most of the survivors go to a new, state-of-the-art school which stands just across the road from the derelict School Number One.

The children refused to give the new school a number, calling it School on Kominterna Street instead.

But five years on the survivors find studying far from straightforward. Almost all suffer from huge memory and concentration problems.

The teachers told me that most of the children display bouts of aggression and bad behaviour, but following the psychologists’ advice, they are reluctant to discipline them. Nearly all the children receive poor marks.

“I have become angry and nervous,” Lana explained. “When I sit at lessons I forget things. They speak and I don’t understand what it’s about. Everything escapes my head.”

All of the children I spoke to suffer from health problems. Persistent headaches and heart problems related to stress are the most common aliments developed as a result of their traumatic experiences.

But what struck me most while talking to children today was how their initial fury and hate towards the terrorists have been gradually replaced and directed elsewhere.

Many, like Laima, blame the Russian government for not having done enough to prevent the attack and for mishandling the stand-off with the terrorists after they had seized the school.

“If the government had satisfied their demands they might not have blown up the gym,” she said.

But with only one terrorist in jail and not a single official found responsible for the attack, some of the children now search for their own answers about what happened and why.

Atzamas was 10 when, on the last day of the siege, the force of the bomb blast knocked him out. He woke up trapped under a pile of bodies.

He says he has tried to understand things from the attackers’ point of view.

“They can’t be the only ones to blame. I have studied their lives, their school of Islam and I thought hard about the war in Chechnya.

“If they were attacked by Russian troops, they were fighting to be free. And then they would want revenge on Russia – after all Russia had been killing their children too,” he said.

Since the attack each of the children has in their own way tried to overcome its legacy and focus on the future.

“I am going to be a doctor. I will have my own clinic where I will treat future victims of terrorism,” Laima told me.

But Chermen has even loftier plans, born out of the sense of destiny his close brush with death has engendered.

“I will grow up to become the president. It’s not a question whether I will or not. It is just a question when,” he said.

Watch Ewa Ewart’s film on the children of Beslan, five years on, on Newsnight on Tuesday 1 September at 10.30pm on BBC Two.