In the northern Nigerian state of Jigawa, four men were found guilty of rape and sentenced to life in prison.
In four separate cases, the state’s highest court in Birnin-Kudu found them guilty of raping four girls.
According to a statement from the state justice ministry, two students, both 8 years old, were attacked by the inmates after leaving their primary schools in two separate incidents.
Ages 6 and 12 were those of the victims in the other incidents.
Some of the prisoners had refuted the accusations made against them.
However, Zainab Baba Santali, a spokeswoman for the justice ministry, claims that medical records were included in the proof that prosecutors provided to the judge.
The convicted rapists are entitled to appeal the rulings.
Campaigners have been calling for harsher action to address the issue of rising rape cases and low rates of punishment for offenders in Nigeria. The issue has been referred to by some as an epidemic.