(http://news.bbcimg.co.uk/media/images/74253000/jpg/_74253710_nigeriachibok4640414.jpg) It is thought Islamist militant group Boko Haram took the girls to forested areas near the Cameroonian border.
Correspondents say the raid on the boarding school is a great source of embarrassment for the Nigerian authorities, who have been saying that their military campaign against the militants is succeeding.
'No intention to deceive' Continue reading the main story (http://www.theinfostride.com/forum/#story_continues_2) Boko Haram at a glance (http://news.bbcimg.co.uk/media/images/74319000/jpg/_74319997_1b90f3e5-64d5-43b9-b311-8df7c2d9466a.jpg)
- Founded in 2002
- Official Arabic name, Jama'atu Ahlis Sunna Lidda'awati wal-Jihad, means "People Committed to the Propagation of the Prophet's Teachings and Jihad"
- Initially focused on opposing Western education
- Nicknamed Boko Haram, a phrase in the local Hausa language meaning "Western education is forbidden"
- Launched military operations in 2009 to create an Islamic state across Nigeria
- Founding leader Mohammed Yusuf killed in same year in police custody
- Succeeded by Abubakar Shekau, who the military wrongly claimed in 2013 had been killed
- Nigerian students living in fear (http://www.theinfostride.com/news/world-africa-24353555)
- What is Nigeria's Boko Haram? (http://www.theinfostride.com/news/world-africa-13809501)
The attack on the school in Chibok, a remote part of Borno state, happened late on Monday with gunmen reportedly storming the school, stealing food supplies and ordering the students onto lorries.
On Wednesday, the military said most of the abducted students had been freed "as troops pursuing the terrorists close in on the den of those believed to have carried out the attack".
But Mr Olukolade said it was based on a report "filed in from the field indicating that a major breakthrough had been recorded in the search".
"The report forwarded to the public on this issue was in good faith and not intended to deceive the public," he said.
"The number of those still missing is not the issue now as the life of every Nigerian is very precious."
On Thursday, a group of parents headed off into the Sambisa forest in a desperate search for their daughters.
It is an extremely dangerous mission, the BBC's Nigeria correspondent Will Ross reports.
The well-armed Boko Haram fighters have killed hundreds of civilians this year, slitting the throats of many of their victims, he says.
Borno, Yobe and Adamawa states in north-east Nigeria have been under emergency rule since last May.
Militants from Boko Haram - which means "Western education is forbidden" in the local Hausa language - frequently target educational institutions.
Source: BBC.co.uk