Parents of the missing Chibok schoolgirls on Saturday marked the fourth anniversary of their daughters' kidnapping by Boko Haram, renewing calls for their release and thousands of others seized in the bloody conflict in northeast Nigeria.
Mothers and fathers were among several thousand people who marched to the Government Girls Secondary School, where 276 girls were abducted on the evening of April 14, 2014.
Fifty-seven escaped in the immediate aftermath and four years on, 112 are still being held – a global symbol of the Islamist insurgency that has devastated the region.
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.
Hannatu Daudu, whose daughter Saratu, is among the captives told the crowd: "Our only prayer is for our girls to be released and returned to us.
"We need to know if they are alive or dead. If they are alive, let them come back to us. If they are dead, let us know so we can at least pray for them and then overcome this grief.
"It is better to know if our daughters are dead than being left in suspense. This adds to our grief."
The Chibok ceremony, which included Christian and Muslim prayers, was one of a number of vigils and protests to mark the four-year anniversary of the abduction across Nigeria.
Nigeria's president in 2014, Goodluck Jonathan, was heavily criticised for his response to the Chibok abduction. Muhammadu Buhari, the man who replaced him, has had more success.
Since 2016, 107 girls have been found, released or escaped as part of a government deal with Boko Haram and the administration has said back-channel talks are ongoing for further releases and a possible end to the wider conflict.
Yakubu Nkeki, the head of the Chibok girls parents association, told AFP: "We are praying for every Nigerian who is in the custody of Boko Haram.
"Let the government do its best to see that every Nigerian citizen in the hands of Boko Haram is released during this year."
Buhari, who is seeking re-election next year, told the Chibok girls' parents their daughters "will never be forgotten or abandoned to their fate".
The former military ruler has repeatedly claimed Boko Haram was virtually defeated but while there have been clear army gains, security threats remain.
In February, fighters loyal to a faction headed by Abu Mus'ab Al Barnawi seized 112 schoolgirls and one boy from the town of Dapchi, in Yobe state.
One hundred and seven were returned in mid-March. Five reportedly died, while one girl – the only Christian in the group is still being held.
Buhari said the return of so many students from Dapchi and Chibok"should give confidence that all hope is not lost" and showed the government was "doing its very best".
Some Dapchi parents were in Chibok on Saturday in a show of solidarity.
Buhari said there had been "unexpected setbacks" in talks because of infighting within Boko Haram.
But he added: "We will continue to persist, and the parents should please not give up."
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.
Unicef said this week more than 1,000 children had been verified as abducted in northeast Nigeria since 2013, although the real figure is estimated to be much higher.
Amnesty International's Nigeria director, Osai Ojigho, said the Chibok abduction was a small part of a bigger issue.
The government needed to deliver "meaningful action on behalf of all these victims of Boko Haram's crimes" and "far more support must also be provided for past victims", she added.
The International Crisis Group, meanwhile, said the copycat abduction in Dapchi showed more needed to be done to protect schoolchildren in the restive region.