He travelled two days by canoe down the Niger River and then 12 hours by bus to the town of Segou, 230km northeast of the capital, where he heard there were catch-up classes.
Oumar, 16, was preparing for exams when insurgents overran his historic town of Timbuktu. The town was first captured in March by fighters from the Movement for the Liberation of Azawad (MNLA) who want an independent state in north Mali. Weeks later, Islamist extremists seized the town from them.
All schools were closed. For five months, Oumar had nothing to do. Many of his classmates and neighbourhood friends joined the Islamic Ansar Dine army but he was not interested.
"After they joined, they stopped talking to me. I would telephone them but they would not answer. When I saw them in the market place with their guns they pretended not to know me," Oumar said.
One of his friends, who had earlier fled to Segou - about 750km south of Timbuktu - called to share the good news about this school with catch-up classes that Plan International was running. He told his mother and as soon as she could afford it, he was on his way.
Girls banned from river
He was happy to put Timbuktu behind him. He said there was a breakdown in civil services. Stores had been looted. Government offices were vandalised. Hospitals and clinics were operating with skeleton staff and little medical supplies. Law and order had broken down in the early days.
Motorcycles were stolen and 4-wheel drives of NGOs were hijacked. Law and order was restored when the Islamists arrived and imposed Sharia law. However, social services remained affected, such as electricity which was restricted to three hours per week.
"I was very discouraged because I could not charge my cell phone, or make ice, or turn on the fan. I could only watch TV three hours per week and only international channels because the Islamists cut transmission of Malian TV, so we did not know what was happening in the country."
"I was very scared, especially at night because of all the shooting. I also saw women being whipped by the Islamist police who threatened to shoot me."
He was bathing in the river with girls as usual. One day they saw the Islamist police coming toward them and they ran. The next day, the police caught them unawares in the river.
"They said to me: 'Yesterday you ran when you saw us coming but we have come to warn you that it is forbidden for girls to bathe in public. If we see you again with the girls, you will not outrun a bullet'."
"I never went back to the river!" he exclaimed, adding that "I didn't want to get married either."
Oumar said that if a single man and woman were caught talking in public, no matter how young they were, they were arrested and ordered to marry. The Islamist paid a dowry, which he heard was 2,000 CFA (US$4), to the girl's parents so the couple could be married without delay.
"When I left Timbuktu, there was a public wedding taking place," he added.
News of the classes in Segou spread by word-of-mouth. It attracted students from all over the north - as far away as Gao (930km) and Kidal (1300km). UNICEF estimated that of the 300,000 school-age students in the north, as many as100,000 of them may have fled to the south.
Fifteen year old Fatoumata came from Gao. She wanted to be a midwife but was denied further schooling when schools were closed after the town was seized.
"I was so scared. There was so much damage to buildings and stores. I even saw a dead woman in the town. For a long time I would see images of these people whenever I closed my eyes. I had difficulty sleeping."
Class sizes swell
After the MNLA took over, law and order broke down.
"Prisoners escaped and terrorised us. We locked ourselves in our homes. They came to the neighbourhood, banged on doors, demanding they be opened - or else. They took what they wanted and left the people unharmed."
When the Ansar Dine arrived, law and order was restored. Fatoumata and all other women had to cover their heads and they had to be so careful never to speak to a man in public or stand next to one in the market place.
"If they see a girl talking with a boy, they would each get 10 lashes, if they were single. If the woman was married, it was 100 strokes each."
After exams, she wants to return to Gao to continue her studies, if schools are open, irrespective of whether there is Sharia law.
The catch-up classes were put on specifically for displaced students. Some lived with relatives and others lived at a boarding school where north Malian cuisine was used for their daily meals in order to maintain as much of their culture as possible.
In the region of Mopti, a few hours drive north, the education ministry also started catch-up classes for displaced students based on the 'Plan model' including using north Malian cuisine.
The displaced students have now been integrated into regular classes with the start of the new school year but the demand for school places in Mopti is so great that the average size of the class runs around 150 students.
"There is a definite need for additional classrooms in Mopti and Plan Mali is aiming to assist with as many as we are able to within our tight budget," said Emergency Response Manager Christophe Mvogo.
"Our appeals for education programming in this emergency have been poorly funded. We wish that we were able to provide many more classrooms and many more teachers."
In the absence of funding, hopefully the students' thirst for education would outweigh the constraints so that they benefit significantly.