"The recent safe return of more than 100 of the Dapchi girls following the determined efforts of the Federal Government, should give all of us confidence that all hope is not lost".
Four years on, 112 are still being held.
Parents whose daughters have been released wore white tabards over their clothes at the two-hour ceremony, while those whose daughters are still being held wore black.
"We are here to show (the) government that we are still missing our sisters", Zakaria Galang, a brother of one of the students who is yet to return, told AFP. If they are dead, let us know so we can at least pray for them and then overcome this grief.
Another activist, Habiba Balogun, said she hoped that would happen after almost nine years of violence that has left at least 20,000 dead and made more than 2.6 million homeless. "This adds to our grief".
"The fourth anniversary of the Chibok abduction reminds us that children in northeastern Nigeria continue to come under attack on a shocking scale".
President Muhammadu Buhari has pledged to ensure the rescue of the remaining Chibok Secondary School girls still with Boko Haram.
Salkida also disclosed that the 15 girls still alive are no longer under the control of Abubakar Shekau, leader of Boko Haram, saying that they have been married off.
Boko Haram, whose name roughly translates into, "Western education is forbidden", seeks to establish an Islamic state in northeast Nigeria, though it has spread its terror across mountainous borders over the years into Niger, Chad and Cameroon, all of which surround the Lake Chad Basin. About five died while in Boko Haram hands.
According to him, as long as he remains the Commander-in-Chief of the Armed Forces, the Chibok schoolgirls will never be forgotten and all will be done to have them reunited with their families. In February, one faction kidnapped more than 100 schoolgirls from the town of Dapchi, previously untouched by the war.
One hundred and seven were returned in mid-March.
The International Crisis Group meanwhile said the copycat abduction in Dapchi showed more needed to be done to protect schoolchildren in the restive region.
Islamist fighters from Nigeria's Boko Haram group have abducted more than 1,000 children in the northeast since 2013, the United Nations children's agency UNICEF said on Friday.
Boko Haram has used kidnapping as a weapon of war during the conflict, seizing women and girls to act as sex slaves or suicide bombers, and men and boys to fight.
"There is something undeniably wrong when its girl-child repeatedly becomes the bargaining instrument in negotiation deals between the government and terrorists".
"What happened in Chibok should have served as a wake-up call to the Nigerian government".