Henrietta Alokha, an administrator at Bethlehem Girls College, Abule Ado, was among those who lost their lives in the explosion which occurred on Sunday morning.
Chisom Udoakonobi, a newly married pregnant first graduate, was also confirmed killed alongside her husband.
The National Emergency Management Authority (NEMA) put the death toll at 17 as of Sunday evening.
A mass celebration was ongoing in the school when the incident happened and Alokha was reportedly among those who assisted trapped students to escape from the scene but when it was time for her to leave, she could not make it out alive.
A couple years ago, there was a less severe fire incident at the secondary school and the Rev. Sister was also there to evacuate students.