Armed men from the mainly Christian anti-balaka militia released a U.N. employee in the Central African Republic after holding her briefly on Tuesday, a military spokesman said.

"We have obtained the release of the employee with MINUSCA (the U.N. peacekeeping mission) and have handed her over," Igor Lamaka told AFP. A Western source confirmed the release.

Armed men kidnapped a female U.N. employee in the capital of the strife-torn Central African Republic on Tuesday, a day after two aid workers were seized, said a source with the U.N. force.

The gunmen, who appeared to be linked to the mainly Christian militia known as the anti-balaka, seized the woman from a van taking U.N. staffers to work in Bangui, the source with the U.N.'s Minusca force in the country said on condition of anonymity.

A 67-year-old French woman was kidnapped on Monday in the capital of the Central African Republic where she was carrying out humanitarian work, the French presidency said.

"France condemns this act... and calls for those responsible to free our compatriot as soon as possible," the presidency said in a statement, adding the French embassy in Bangui was in constant contact with the archbishopric which was holding talks with the kidnappers.

A powerful vigilante leader in the Central African Republic, accused of masterminding a massacre of some 300 minority Muslims in December 2013, has been arrested, prosecutors said Sunday.

U.N. peacekeepers arrested Rodrigue Nagibona, alias General Andjilo, who had been on the run for several months, on Saturday in the northwest of the impoverished country and took him into custody, the prosecutors said.

Nearly 100 people are feared missing in the Central African Republic after a boat caught fire and sank on a river in the strife-torn country this week, officials said Thursday.

The sinking happened on Monday after the boat's motor exploded, starting a fire that quickly engulfed the vessel, with terrified passengers jumping overboard, officials told Agence France Presse.

Captured Lord's Resistance Army rebel chief Dominic Ongwen was handed over Wednesday to African Union troops to be sent to trial at the International Criminal Court for crimes against humanity, Uganda's army said.

Ongwen, who surrendered last week and was in the custody of U.S. special forces in the Central African Republic, has been sought by the ICC for almost a decade to face charges including war crimes, murder, enslavement, inhumane acts and directing attacks against civilians.

Recent violence between rival militia groups has claimed at least six lives at Bambari in the center of the highly unstable Central African Republic, police said Friday.

"Five people were killed and several injured between Tuesday and Wednesday in clashes that erupted in Bambari between two anti-balaka ("anti-machete") groups for reasons not yet known. The victims were, for the most part, anti-balaka," a police source told Agence France Presse on condition of anonymity.

Ugandan army officers have met a top commander of the notorious Lord's Resistance Army (LRA) rebels who is wanted by the International Criminal Court and in U.S. custody, Uganda's defense minister said Thursday.

LRA commander Dominic Ongwen, who faces trial at the ICC for crimes against humanity and war crimes and was one of the last senior aides to LRA leader and warlord Joseph Kony, surrendered this week in the Central African Republic.

Boko Haram's seizure of a key town and military base in Nigeria's far northeast has tightened its grip on the region, undermining efforts to tackle the insurgency, experts said on Tuesday.

The capture of Baga and the headquarters of the Multinational Joint Task Force (MNJTF) now means the Islamists control all three of Borno state's borders with Niger, Chad and Cameroon.

At least 18 people have been killed and dozens injured in fresh attacks in the Central African Republic, where dozens have died in a new flare-up in inter-ethnic violence, officials said Tuesday.