As many as 300 teenaged girls were abducted from their school in Nigeria exactly one month ago on April 15 by the Islamic militant terror organization Boko Haram. The group is based in Nigeria and has carried out attacks on schools before.
Some girls managed to escape, but many are believed to have been transported into neighboring Cameroon or Chad.
The leader of Boko Haram, Abubakar Shekau, has said he plans to sell the girls into marriages and sex slavery, but now says he is willing to exchange them for imprisoned militants
The U.S. has sent manned and unmanned surveillance planes to the border area of Nigeria to help search for the girls, along with local Nigerian herdsman carrying bows and arrows.
The British government has pledged one of its planes equipped with radar that is able to track human movement on the ground.
France, China and Israel have pledged to share satellite imagery and intelligence.
The Nigerian military said this week that they have brought additional troops to the border area but have not yet entered the Sambisa forest area, one of the main areas the girls are believed to be.
Nigerian Military, Villagers Under Threat by Boko Haram
Villagers in nearby states launched an attack on insurgents, killing and detaining many of them as a precaution against a Boko Haram attack this week, according to the Associate Press.
Meanwhile, Nigerian soldiers were ambushed by insurgents on a remote road and, after a fire fight, the soldiers began firing at their own commanding officer, according to the AP.
Negotiations with Boko Haram
Nigerian officials told ABC News earlier this week that they were having high level discussions with leaders of Boko Haram about returning the girls, but they would not say whether they were negotiating or what the terms would be for the return.
President Goodluck Jonathan has ruled out a prisoner swap with Boko Haram.
What Else is the World Doing?
A late-night vigil was held Wednesday in Abaju for the missing schoolgirls to mark 30 days since the kidnapping.
Michelle Obama used the president's weekly radio address last weekend to issue a plea for the girls' safe return.
Protesters across Nigeria continue to rally to draw attention to the plight of the girls.
The Twitter hashtag "#BringBackOurGirls" has been trending at various points since the girls were taken, with many users from around the world demanding a swift rescue of the girls.