South Sudan was never an easy country to work in. We lived behind razor-wire topped walls, we weren't free to walk around on our own and for many NGOs, 10pm curfews were the norm. But, until fighting broke out in Juba last week, it was home. I formed great friendships with local people, and I was excited for what seemed like an abundance of opportunities for the world's newest nation.

As we, the expat community, are safely airlifted out of South Sudan and sent home, I feel we have an obligation to tell the story of those who will really suffer, those left behind. For me, that is my colleagues and friends from Confident Children out of Conflict (CCC), where I have been living for the last ten months. CCC is a local NGO that provides a safe and loving home to 40 street girls. These girls, along with the team of staff looking after them, became my family in Juba.

Hannah's cramped evacuation flight from Juba to Addis Ababa, Ethiopia. Photograph: Hannah Rounding

I didn't want to go. I saw it as running away; abandoning people just when they needed us the most. But the office told me I had to. I was supposed to take a British military evacuation flight but I walked away from an airstrip littered with people's abandoned belongings as we were being forced to board the plane to Uganda with only our passports, wallets and phones. We had already spotted armed SPLA (South Sudan People's Liberation Army – the government's military body) hawking over the left luggage. At the last moment I decided I could not leave South Sudan like this. The following day I was evacuated on a Dutch air force flight to Addis Ababa.

I still don't know how, but I actually slept through the first two lots of fighting the night of the first attacks. It was only the third round, coming from the army barracks closest to us, that finally woke me at around 6am. Hearing gunshots in Juba is not uncommon but straight away I knew that this was different. I opened my door. Cathy, CCC's director, was also on her doorstep. Both of us were wrapped in bath towels. We looked at each other as we listened to rounds and rounds and rounds of machine-gun fire and continuous shooting. Then I heard the blasts. Like the sound of bombs. This went on for over four hours.

CCC has girls as young as five living in the home. That first morning the dormitories smelt of urine and the floors and bedsheets were wet. Only the very youngest of these girls have grown up in a country free of war, until now.

During these days in Juba, unable to leave the compound, we flicked between phones, radio stations, local news sites, Facebook, Twitter and Skype, hearing stories from friends and colleagues across the country, trying to understand what was happening.

We had three consecutive nights of fairly serious fighting in Juba. After the second night one of the girls, Jogoli asked me: 'Auntie [we all get called Auntie at CCC] has the shooting – the bang-bang – has it stopped?' I felt I had to tell her yes. Every evening that week we sang Christmas carols and did yoga at dusk (before the shooting would invariably start).

I had started to do yoga with the girls in my early days (though they still call it yoghurt!). We did yoga every night for three nights. On the third night, when I was supposed to take the British evacuation flight, to my amazement the girls were finally calm and peaceful as they bent into downward dogs and cat stretches. Just as we were finishing, I saw the enormous Royal Air Force plane rise into the sky. "That's my plane!" I shouted. The girls fell out of their poses and started jumping up and down in the air, waving and calling bye-bye to my plane. It was a real moment – watching my evacuation plane go without me.

I'd been working with an organisation supporting independent journalism and media in South Sudan. Locked up in CCC, I spent two days in my room gathering stories from the field. Stories included those from the staff of CCC who live in some of the worst affected areas of Juba. As they gradually dared to come back to work, they told us how they saw three truck loads of dead bodies (both soldiers and civilians) being taken away by the military after that first night of fighting.

One staff member told us how her neighbour took a sheet off her bed to cover two dead bodies that had been left outside her house. During the two days these bodies lay on the ground, three SPLA trucks had stopped, looked at them and driven away. Apparently the army were only collecting bodies of people who belong to the Dinka tribe – South Sudan's largest ethnic group to which the president, Salva Kiir, belongs.

The media and government are reluctant to admit that this conflict is tribal, but from all the reports I've been receiving it seems clear the fighting and killing is very much along tribal lines. Staff told us that presidential guards were entering people's homes; if they found someone who was Nuer (the second largest ethnic group, to which the former vice-president, Riek Machar, belongs), they were shot. Women and children were not spared.

Bor, the state capital of Jonglei has been one the worst affected areas. My friend Daniel, a teacher, lives there. It took me a long time to get hold of him as the government had cut many of the phone networks, but when I finally did he told me he was hiding in scrubland by the roadside, 10km from town. I asked him how many people were with him, he told me 'thousands, half the town'. The other half had sought refuge in the UNMISS (UN Mission in South Sudan) compound, which we later learnt was attacked by rebels.

Daniel told me he saw his neighbours, three young men, killed that morning: one shot in the head, one in the chest and another slit at the throat. He told me that Nuer soldiers were killing the Dinka soldiers and civilians – the opposite of what was happening in Juba. He told me a mother and her children tried to swim across the Nile to safety. Her children drowned.

Our staff were amazing during these days – collecting stories and reports to let people know what was really happening. Some took on dual roles – reporting during the day, and working in the hospitals at night. It is these people we have left behind and who continue to witness what is really happening in South Sudan. It is their story.

We left in complete uncertainty; we have no idea what the future holds for South Sudan. Things could get better, but things could also get a lot worse. There were chances in the early days for dialogue that could have stopped the violence spreading to other states, but none were taken. People talk of it being on the brink of civil war. For me I find it hard to believe that the leadership of South Sudan would really be willing to put their people through this all over again after a history of such suffering and also after so much progress was made.

The South Sudanese are divided on whether it really was a coup or not but one thing everyone agrees on is that the leaders who are supposed to protect their people are the very ones responsible for this terrible situation. How trust can be rebuilt now is hard to imagine.

If things get any worse the 40 girls at CCC – who, remember, have already been through so much horror and suffering – will have to move to Uganda for refuge or hide in the bushes, fending for themselves. Just the same way they did during the last war. Cathy will remain with them until the very last minute, that I know.

My work colleagues will continue to gather stories and report accurately on the situation out there. They will make sure that people within and outside of South Sudan are told what is really happening on the ground.

For those of us who were forced to leave, we will go back when we can.

Further information about CCC can be found at www.confidentchildren.org

• This article was amended on 26/12/2013 to protect staff working in independent media organisations in South Sudan