A fire in the rebel-controlled city of Bukavu, in eastern Democratic Republic of the Congo, has killed at least 20 people, including primary school students, according to local officials and medical sources.

The blaze broke out at around 8am local time on Thursday in the Chimpunda district of Bukavu, South Kivu's provincial capital. It spread to the Ujamaa and Furaha primary schools and a nearby residential settlement.

An official from the rebel administration put the death toll higher, at 24 — 19 girls and five boys. Dunia Masumbuko Bwenge, who serves as vice governor of South Kivu under the Rwanda-backed AFC/M23 movement, said 29 others were injured.

A nurse at a local clinic said at least 14 children were among the dead, all under the age of 10.

"We received around 50 students, including several teachers, in a critical state of asphyxia," said Christophe Zigashane. "Among them, 10 were dead and four others died at the scene. That makes a total of 14 deaths, all under 10 years old."

Local leader Patrice Buduge described scenes of panic during the incident. The fire was "followed by a violent stampede that forced students to trample over one another or look for a dangerous way out; many of them fainted and others lost consciousness," he said.

Several people were treated for smoke inhalation, with some reported to be in critical condition.

The blaze also destroyed between 300 and 500 homes and a clinic in the area, according to local media. Verified footage showed the fire consuming a number of houses before the flames reached the two schools.

Authorities said the death toll remained provisional and the cause of the fire had not yet been established.

Local media noted that Bukavu has experienced several fires in recent days, including a separate blaze last Sunday that destroyed more than 45 houses.

Bukavu has been under the control of AFC/M23 rebels since the group staged a rapid offensive in eastern DRC last year.