For a dozen young boys in central Mali, this is a crucial day. Wearing royal blue cloaks with pointed hoods, the boys line up beside the road in a small village just outside the city of Ségou, chanting in unison. In the eyes of their community these children have just become men. They shake musical instruments made from calabash bowls strung from sticks to signify that they are emerging, circumcised, for a public celebration of manhood.

The event has assumed an air of defiance in Ségou, a region now engulfed by a battle for control of the country.

The road beside the boys is busy with traffic – convoys of aid agencies driving south, instructed to leave after the security alert was raised to red, the highest level. Heading north are army trucks transporting supplies. Earlier in the day, they were carrying French and Malian soldiers.

Mali government troops have been fighting the al-Qaida-linked Islamists controlling the north of the country for almost two weeks now and the campaign is beginning to take its toll. Wounded soldiers are arriving at the main hospital in Ségou, the Hôpital Nianankoro Fomba, in a trickle that hospital officials think will become a flood.

"We are expecting an influx of wounded soldiers from the ongoing fighting in Diabaly," said one official, who did not want to be named. "We are using up our supplies to treat those who have already arrived, we are worried that they will not be replaced."

There are already 10 soldiers and one civilian who were wounded in Diabaly by bullet fire – a significant chunk of the hospital's 134-bed capacity. When the Guardian visited, one soldier was being evacuated to Bamako for urgent specialist treatment.

In a far corner of the hospital grounds, wounded soldiers are recovering on metal beds, two or three to a room. Ibrahim Traore, 41, was wounded in Diabaly on Monday. "My leg was fractured by a bullet," he said, lifting a tatty sheet to reveal a thick white plaster cast. "There was an exchange of fire between the army and the jihadists. They are well armed, they are very well equipped, and there were many of them.

"Now that the French have bombed Diabaly, the jihadists have fled," said Traore, a corporal who was based in Diabaly for seven months before he was injured on Monday.

Traore said that the rebels came to the town from Lére, a town further north bombed by French fighter jets. "There was a huge group of Islamists in Lére," he said. "When the French began bombing Lére, they split into three groups. One group came to Diabaly."

As the rebels have moved south, so have thousands of civilians. The Sido Soninkoura school in Ségou houses many displaced children, some of whom are supported by the charity Plan International – which helps them with exercise books, blankets and sanitary items. The children wear well-worn bomber jackets, gloves and ear muffs to protect them against the winter, as January in Mali brings a mix of scorching sun, dusty wind and relatively cool air.

Almoukamatou Dicko, 15, left her hometown of Gao three months ago with her sister, after rebels murdered her headteacher to steal his moped.

"I was scared when I left Gao, I came to Ségou because my big sister is here," said Almoukamatou quietly, fiddling with the orange and green tie-dye robes often worn by women in northern Mali. "My sister's husband is a professor, he has found work teaching here, so we are managing. But I miss my mother, and I'm worried that bombs are falling on my town. We don't want bombs."

Fatou Malafa, 17, came to Ségou eight months ago from Timbuktu with 16 relatives. She is slim with fair skin and long braids, and speaks confidently about her ambition to be a journalist when she finishes school.

"I came to Ségou with nothing, I left all my belongings, and all my books," she said. "I used to love reading novels, but I don't have any here, and where we live there are no lights. I do my homework with the torch on my mobile phone."

Fatou says her family owned a restaurant in Timbuktu, which baked bread and served rice dishes and coffee. "When the rebels arrived, they told people not to come to our restaurant, especially women," she said. "For girls, they took away our right to go out."

Fatou and Almoukamatou are typical of many of the once relatively well-off Malians who have fled the Islamist control, often so that they could continue their education after rebels closed down schools. But the new wave of fighting has changed that, and newer arrivals in towns like Ségou are no longer seeking education, but fleeing for their lives.

At the district social services headquarters in Ségou – a once grand building with an ambitious atrium of now thirsty plants – Ada Marica, 27, is slumped on a chair overcome by dizziness. She arrived in Ségou on Friday having fled the threat of fighting in Mopti. She speaks no French, but explained in the Peul language how her husband had left first, and she and her three children followed, planning to reunite in Ségou. He is missing.

"I don't know where he is, his phone is not going through. I am worried," Marica said. "All I can think of is finding him, since we arrived I have not slept."

Her husband earned a living making chicken feed out of dried fish, while she kept house and looked after their two children.

"We have no money now, and not enough food," she said, distressed. "We came to Ségou to stay with a host family – family friends of my mother's – but they do not have the means to support us, so I have come here hoping social services can give me money and food."

Officials at the social services office say there is little they can do to provide immediate assistance to people like Marica. "We don't have the means to do anything straight away to help," said Ibrahim Almahadi, director of social and economic protection at the social services office. "We are worried about what is happening in Diabaly," he added. "There are many wounded people coming to Ségou for medical treatment. We hope that the French will liberate the town."