YAOUNDE, Jan. 20 -- A United Nations staff working in Bangui, capital of Central African Republic (CAR), was kidnapped near Bangui airport on Tuesday by Christian militants anti-balaka, sources said.

On Monday, the militants took two charity workers in Bangui, one is a 67 year-old French lady and the other one local. A source said the negotiation between the government and the anti-balaka is underway, but there is no result so far.

Another source told Xinhua that purpose of the kidnapping is speculated to be pressing the release of an anti-balaka leader who was arrested by the UN peacekeepers recently.

A civil war in CAR broke out on Dec. 10, 2012 between Seleka rebel coalition and government forces. Seleka took power from the then president Francois Bozize in March 2013 and the rebel's leader Michel Djotodia declared himself as president.

Elected provisional president by a National Transitional Council in April 2013, Djotodia was forced to quit power in January 2014 amid worsening violence between Christian anti-balaka group and Muslim Seleka. Catherine Samba-Panza was elected as provisional president by the National Transitional Council and remained in power since then.