Image copyright Diana Markosian

On 1 September 2004 Chechen militants took more than 1,000 people hostage at School No 1 in Beslan, North Ossetia, among them university lecturer Aneta Gadieva, her nine-year-old daughter Alana, and one-year-old Milena. When a deal was struck to allow some mothers to take out one infant, she faced an impossible choice which, as she explains here, still haunts her.

The first day of the school year in Russia, 1 September, is a happy occasion known as the Day of Knowledge. Children put on their best clothes and bring flowers but they don't take their school rucksacks because there are no classes - it's a day of celebration and catching up with friends. Parents come along, and if a child is starting school for the first time the whole family will be there - grandparents, uncles, aunts, everyone. So there were more than 1,000 people in the playground of School No 1 that day. There were balloons everywhere. Children lined up in their school uniforms and it was a jovial, wonderful atmosphere.

I was just chatting to Alana's teacher when all of a sudden we heard the sound of a machine gun behind us. I turned around and saw with horror that a man was shooting and shouting "Allahu Akbar". My first thought was that he was mad, but then I heard another machine gun on the other side of the school and realised that we were under attack.

I looked around for an opportunity to escape but I couldn't leave Alana, who was somewhere in the playground. I tried to reach her but it was madness, there was a mass of people running towards me. I fell down, still holding Milena, and lost a shoe. I thought we were about to be crushed, but a woman stopped to help us up.

I had this physical wish to push my children back into my belly Aneta Gadieva, Beslan mother

I kept thinking the same thought over and over: "Where is my girl? Where is my girl? I'm not going to see her any more."

The gunmen were smashing windows and forcing everyone into the gym. One of them pushed me through with his machine gun.

The conditions inside were terrible. If there is hell on earth, that was hell.

There were 1,200 people crammed into a small gym. There wasn't room to stretch out an arm or a leg so we were all twisted and squashed into each other. It was horrible. And of course I had a baby in my arms.

I found a table and sat on it, looking out for Alana, crying, calling out her name. Then one of the parents said: "There is Alana, she's just over there in the other corner!" And I finally saw her. She waved at me. I wanted so much to be with her. There was a kind of path separating the crowd that the terrorists used to walk up and down, so I told Alana to crawl towards me along this path, while I started walking towards her. She was scared. "Mum, don't go because they're going to shoot you," she said. But eventually we were reunited and hugged each other.

Media playback is unsupported on your device Media caption The Beslan siege remembered

At the start of the siege one of the parents tried to calm everybody down - Ruslan Betrozov, the father of two boys in the school, was speaking to us in our native language, Ossetian. Then one of the gunmen walked up to him and shot him from behind. They dragged his dead body from one side of the gym to the other, in front of his sons.

Then the terrorists started hanging explosives along the perimeter of the gym. They made high school students help them hang bombs from the basketball rings. One boy was supposed to hang a bomb right over our heads and he couldn't. He kept saying that he didn't want to and he was scared it might explode. I told him to hold Milena so I could help, but they wouldn't let me, so he had to hang up the bomb on his own.

We were told that the water had been poisoned so we were too scared to drink it Aneta Gadieva, Beslan mother

Then they installed two pedals on the floor to trigger the bombs, and put a terrorist on each. They just stood there, and the whole time we thought that if they moved, the school would blow up.

I couldn't accept that it was really happening. I kept thinking: "In a moment I'm going to wake up and it will all be gone."

I had this physical desire to push my children back into my belly, so they wouldn't have been born, so they wouldn't be there.

The other dilemma I had was how to protect them if there was an explosion. How would I do it? I even tried stretching out to see whether I would be able to cover both of them.

My neighbour Fatima was there with her children aged 10 and four, and her baby girl, Alyona, who at eight months was even younger than Milena. Alyona was crying so much that the terrorists couldn't stand it and so at lunchtime they were all taken out - where to, we did not know.

Image copyright Getty Images

But later that night we saw each other again when all mothers with children under the age of three were sent to join them in the changing rooms. I took Alana with me, even though she was older. Conditions there were a little better - there was a shower, but we were told that the water had been poisoned, so we were too scared to drink from it. Eventually some people started taking small sips because they were so thirsty, but we were too scared to give any to the children.

By the second day, the conditions in the changing rooms had deteriorated badly. There were about 20 very young children, who just couldn't understand what was going on. They were hungry and crying all the time - it was really loud. There were no toilets and we were standing in pools of urine.

In the early afternoon a rumour spread that an important man was coming to visit. One of the terrorists kept running up and down. At first we thought it might be Putin, but later we found out that it was Ruslan Aushev, the ex-President of Ingushetia, who was coming to negotiate.

Find out more

Aneta Gadieva first told her story to TV journalist Alina Gracheva. Like many journalists who reported from Beslan, Gracheva was deeply traumatised by the experience, but her report was nominated for an Emmy.

Then one of the terrorists came in to the changing rooms and said that each woman could take one baby out. I walked up and asked him if Alana could take her baby sister out instead of me. Where to, I didn't know, so it was really scary - to leave a child is awful, frightening, especially when you don't know the outcome.

But he got really angry and shouted: "What did I say? One mother and one breastfeeding infant!"

To be honest, there was no time to think, everything was happening so fast. They kept on shouting: "If you don't go, someone else will suffer for it. If you don't do what we say, someone else will pay the price." They constantly used this sense of collective responsibility against us.

For me, at that moment, there was no choice.

So I dashed up to Alana, who was with another girl from our courtyard, and I said: "Alana, you two stick together, everything will be OK."

Then I walked out with Milena.

What was going on in my head was pure horror.

They shouted at us: "Faster, faster!"

We walked through the smashed-up corridor and there was this dark silence in the school playground. We didn't know what was going on. I still don't, now.

Image copyright Getty Images

Twenty-six of us were released - 11 mothers and 15 babies. Several of us had to leave older children behind.

But Fatima, my neighbour, had refused to move. I don't know how she did it, but she stayed behind with her two older children and gave her youngest daughter to Aushev, who took her to the medical station.

When I saw that Fatima was not there but her baby was, I thought: "How did she do that? I could have stayed behind as well." That was another horrible moment. I felt so terribly guilty.

They took us to hospital, asked us questions, and in the evening they took us home.

I was in such a panic that I kept trying to go back to the school, but my mother wouldn't let me. She kept saying nobody else could take care of Milena, because I was still breastfeeding her. But I was frantic. In the end she fell on to her knees and said, "Please don't go."

Image copyright Getty Images

On the third day I heard a rumour that children were going to be released. I immediately started running towards the school, but before I could get there the explosions started.

I wasn't allowed through so I ran to the hospital and waited there. The first car with casualties arrived, then a second and a third, but none of them had Alana inside.

There were also cars that were going to the mortuary, but I didn't even want to look at those. I couldn't believe that they could just kill children like this. So I just kept on waiting outside the hospital.

Image copyright Getty Images Image caption Relatives check the lists of injured at the hospital in Beslan, 4 September 2004

Then my husband, Seyfil, came back from the school and told me that there was no-one left in the gym, that everyone had been burned. I collapsed.

We kept on looking. For two days we visited all the local hospitals. Then on 5 September my nephew went to the mortuary in Vladikavkaz, the regional capital. He called me to ask what Alana had been wearing. Then he began describing her earrings. That was when I realised she was dead. I fell down and started screaming.

Two of the other mothers who were released also lost their older children and have to live in the same condition as me. Fatima was killed, with her older daughter, but her four-year old survived, miraculously. You never know how God protects you.

After the explosion I couldn't think about anything but Alana. Looking after Milena was impossible. I didn't have the emotional capacity for anything or anyone else.

Image copyright Aneta Gadieva Image caption Alana at the piano

I just wanted somebody - somebody kind and affectionate - to take her away so I could grieve. Our friends came to take Milena out for walks, but my family realised that they couldn't take her away from me altogether because she was my only reason to survive. I needed to take care of her and I needed to give her attention. And eventually I did.

In the apartments where we lived, 38 people had died in the terrorist attacks. We were always together, and could think about nothing else. We were always in this battle, reliving the past - that's what we did all day long. Maybe it was our way of surviving, maybe this adrenaline, this feeling of fury was the thing that prevented us from killing ourselves. Because I just didn't want to exist. I didn't want to live any more. My desire at the time was just to disappear in thin air so that nobody would remember anything about me.

Milena of course makes me go on and I feel like I should live for her Aneta Gadieva, Beslan mother

Then my mother said that I needed to get away, and in May 2005 we moved to Vladikavkaz, about 25km away.

I didn't want to leave Beslan, it was very difficult for me. But when we left it became a tiny bit easier to cope.

One person who did me a lot of good was a Russian doctor who lives in the UK. After she saw my story on television she wrote and invited me to spend time with her. In the beginning I couldn't even think about it, but she kept on insisting and eventually convinced me to visit her in Grimsby. She was so affectionate, warm and tender - I don't think anybody has ever been so kind to me.

I couldn't work for three years. I went back part-time, but soon realised that I was no longer fit for teaching because every once in a while I couldn't help myself and I would tell my students horrifying stories. So I decided to leave. Now I work as a researcher at the Academy of Sciences.

My whole reality, my entire life, was shaped by that day. Milena of course makes me go on and I feel like I should live for her. But then I also feel selfish, because for all these years she's had to live with a grieving mum.

Alana was an important part of Milena's life, not least because she was constantly compared to her sister. But when she was a little bit older she started telling me: "Mum, I'm not Alana, I'm a different person altogether."

Image copyright Aneta Gadieva Image caption Milena loves dancing

She's been through a lot and she misses her sister, but she's remarkably adaptable. Over the years she has developed a mechanism to protect herself - she just puts negative things aside. I ask her how she does it, and she says: "Mum, if I pay attention to everything I'll go crazy."

Alana was very wise too - I remember when she was nine, she said: "Mum, why are you thinking about yesterday? That has already passed."

Milena is very creative, very innovative. She's passionate about dancing and also really interested in journalism. She has an opinion about everything.

She's very independent, even though I am very protective.

When she first started school, it was very hard for me. I couldn't stop thinking about it. Even the sight of a school rucksack was terrible. But life has its own demands and I couldn't stop her from going to school, even though I was constantly worried.

But I never allow her to attend school on 1 September because that's when I go to the commemoration events in Beslan.

Image copyright Getty Images

Last year Milena came with me for the first time. She carried Alana's portrait in the procession from the school ruins to the cemetery. She said it was very important for her.

There are two stories about her sister that Milena loves to hear.

Once, Alana was sick with a high fever and had to go to hospital. I was pregnant at the time but I hadn't told her yet - she kept asking me for a brother or sister and I wanted it to be a surprise. But when she was so weak and feverish I decided to tell her: "You're going to have a brother or sister." She was so happy that she started crying. Her temperature dropped, and for the rest of my pregnancy Alana didn't fall sick once.

The other story is about how, when Milena was born, Alana came to the hospital and just grabbed hold of her baby sister and carried her out of the hospital.

These stories make her happy.

Image copyright Aneta Gadieva

Translation by Tatyana Movshevich

Listen to Aneta Gadieva speaking to Outlook on the BBC World Service.

Subscribe to the BBC News Magazine's email newsletter to get articles sent to your inbox.