It has now been a year since 276 girls were abducted from a secondary school in northern Nigeria by Nigerian militant Islamist group Boko Haram, and 219 are still missing.
Ceremonies are being staged around the world to mark the anniversary.
BBC News looks at what we know a year on.(http://ichef.bbci.co.uk/news/200/media/images/75306000/jpg/_75306515_line976.jpg)How many are missing and where are they?On 14 April 2014, 276 girls were kidnapped from a government secondary school in the northern Nigerian town of Chibok, Borno state, by Boko Haram. (http://ichef.bbci.co.uk/news/200/media/images/78211000/jpg/_78211500_022230424-1.jpg) Boko Haram released a video appearing to show the girls in May last year Some 57 escaped, but 219 are still missing. There have been reported sightings of the girls, but none has been found and there has been very little official information released by the government.
On Monday, a resident of the north-eastern town of Gwoza who asked not to be identified said she saw the girls three weeks ago as they left a large house close to her home.
They told her the building had been bombed and some of the girls were injured. It is not clear where the girls are now.
Escape from Boko Haram (http://www.bbc.co.uk/news/world-africa-29762252)(http://ichef.bbci.co.uk/news/200/media/images/75306000/jpg/_75306515_line976.jpg)What's been done to find them?The Nigerian government says it has responded with a military offensive, but also attempts at dialogue and negotiation to secure the release of the Chibok girls in exchange for detained Boko Haram fighters.
In October last year, it even got to the point of declaring a ceasefire as a pre-condition to negotiating with Boko Haram, including over the release of the Chibok girls. (http://ichef.bbci.co.uk/news/200/media/images/82303000/jpg/_82303387_026713342-1.jpg) The girls were seized from a school in Chibok But there was no peace deal and the government never explained how it had got this so badly wrong, says the BBC's Nigeria correspondent, Will Ross.
In an interview conducted two weeks ago - before he lost the election - the outgoing president of Nigeria, Goodluck Jonathan, said it was a shame that politics had come before the welfare of the girls.
He blamed the rival political party governing Borno state for the initial confusion when the girls were abducted.
"There's so much about these girls that one can't even comprehend. So much of - more of politics than concern about the girls, and the stories are twisted and painted different colours."
Will Nigerian schoolgirls ever be freed? (http://www.theinfostride.com/forum/29612345%20-%20Will%20Nigerian%20schoolgirls%20ever%20be%20freed?)(http://ichef.bbci.co.uk/news/200/media/images/75306000/jpg/_75306515_line976.jpg)Has the offensive against Boko Haram made any difference?The offensive against Boko Haram has not helped much in the effort to secure the release of the Chibok girls.
The belief was that Boko Haram was holding the girls in one of the Nigerian territories under its control. (http://ichef.bbci.co.uk/news/200/media/images/82303000/jpg/_82303392_026690969-1.jpg)The Nigerian military in the past also said it knew where the Chibok girls were being held, but did not take any action to rescue them so as not to jeopardise their safety.
But now that militants have been driven out of most of the Nigerian territories they previously held, the Nigerian military says it does not know the girls' whereabouts.(http://ichef.bbci.co.uk/news/200/media/images/75306000/jpg/_75306515_line976.jpg)Will President-elect Buhari make a difference?There is a lot of hope President-elect Muhammadu Buhari will approach the issue of rescuing the Chibok girls and the Boko Haram insurgency differently. (http://ichef.bbci.co.uk/news/200/media/images/82303000/jpg/_82303390_026699819-1.jpg)He won the election on an anti-corruption platform - he blamed what he called the rot in the Nigerian military on entrenched corruption, which he promised to cleanse as a former military man.
But some critics point out that he will have to work with the same military that failed to rescue the girls. His supporters say a different approach is therefore needed to yield different results.
However, on the first anniversary of the abduction, Mr Buhari said in a statement that he could not promise to find the missing schoolgirls and that their whereabouts were unknown, adding: "We do not know if the Chibok girls can be rescued".
Source: BBC