Chad announced Thursday it was withdrawing from the African peacekeeping force in Central African Republic after being accused of siding with a mainly Muslim movement that seized power last year.

Chad came under the spotlight at the weekend when at least 24 people were killed and another 100 seriously wounded by Chadian soldiers sent to repatriate their compatriots from the CAR, according to officials there.

The U.S. military's partnership with France in Africa is "indispensable" in the fight against extremist groups in the Sahel region, French Defense Minister Jean-Yves Le Drian said on Friday.

During a visit to Washington, Le Drian said "terrorist groups are circulating across the whole Sahara-Sahel area and terrorist acts could put our own security at risk."

Chad's President Idriss Déby Itno on Friday vowed that attacks on Chadian nationals in the restive Central African Republic would not go "unpunished".

While visiting families repatriated to Ndjamena, Deby said that "attacking women and children, and targeting Chadians, assassinating, killing them is intolerable," according to an Agence France Presse correspondent at the scene.

Hundreds of Chadian civilians prepared Saturday to flee to their home country after facing repeated attacks and threats from majority Christians in the strife-torn Central African Republic.

The Chadians were seen piling into a convoy of several dozen cars and taxis in the capital Bangui under the taunts of angry residents looking on.

Chadian troops in a Central African Republic peacekeeping force will be redeployed from the capital Bangui, a force spokesman said Wednesday amid charges they were siding with a former rebel group.

The announcement came as exchanges of gunfire erupted Wednesday in several parts of Bangui, including near the airport, residents and witnesses said without giving details about who was involved.

African Union troops early on Monday fired on demonstrators protesting against the president of the strife-torn Central African Republic, killing at least one person, according to Agence France Presse reporters on the scene.

Several hundred Christian demonstrators crowded at the entrance to the airport in Bangui, calling for the departure of President Michel Djotodia, who became the first Muslim leader of the majority Christian nation after a March coup that unleashed waves of violence in the country.

Chadian troops in a joint force with Sudan have been killed battling tribal fighters in the troubled Darfur region, a humanitarian source said on Saturday.

The source did not know how many Chadians died in Thursday's fighting with Salamat tribesman around Umm Dukhun, a town on the border with Chad in southwestern Darfur.

Rights group Amnesty on Thursday accused Chad of killing and illegally detaining its critics and demanded it stop using "repressive" tactics against opponents.

"People are dying in detention, held incommunicado and arbitrarily arrested left, right and center," said Amnesty's Christian Mukosa, as the London-based group released its report "Chad: In the name of security?"

More than 1,000 alleged victims of former dictator Hissene Habre are suing him in Senegal, where he is being tried for genocide during his eight-year rule of Chad, their lawyers said on Wednesday.

Habre, 70, faces accusations of war crimes, crimes against humanity and torture during his brutal rule between 1982 and 1990, when some 40,000 people were killed, according to rights groups.

Nigeria's presidency on Monday defended welcoming Sudan President Omar al-Bashir to the country for an African Union health summit despite war crimes charges against him, saying it cannot interfere in AU affairs.

Bashir arrived in the Nigerian capital Abuja on Sunday for the summit on HIV/AIDS, turberculosis and malaria despite being wanted by the International Criminal Court on charges of war crimes, crimes against humanity and genocide.