The group, he explained, is at Iwawa Island undergoing re-training and re-education to enable them easily re-integrated into the Rwanda Defence Forces and Rwandan society.
Nzabamwita's remarks came in the wake of allegations that the RDF was illegally detaining the ex-combatants and hiding them from humanitarian activists visiting the island.
"After deserting RDF and leading a life of hiding from authorities, they were arrested and spent some time in detention at Mulindi Military prison," said Nzabamwita in an email to The New Times.
Nzabamwita also added that, "The RDF leadership opted to retrain them and consider whether some of them would go back to active service or be officially discharged."
The soldiers, according to Nzabamwita, were arrested from different places around the country and that they all belonged to different battalions.
The Iwawa Vocational and Training Centre, under the Ministry of Youth and ICT offers vocational and civic education for youth delinquents.
"The facilities are a perfect institution where the RDF soldiers, alongside their compatriots undergo a similar programme, on top of military drills in particular that enhance military discipline," the Spokesperson added.
He stressed that that the soldiers are not being held incommunicado, saying visits by national leaders, parents and other guests take place.
Reports from UK-based media indicated that alleged deserters were transferred there a year ago from a military prison to prevent a planned visit by the Red Cross, a claim Nzabamwita dismissed.
"ICRC has particularly visited Iwawa in July 2012 to meet this group that was originally detained at Mulindi Prison. Currently 13 out of the 283 soldiers are visiting their families. It is public knowledge that this group is in Iwawa, much as there are other Rwandan youth undergoing a similar programme," he added.