Hundreds of deserting Central African Republic soldiers and police returned to their commands on Monday as the interim president said "the party is over" following weeks of deadly sectarian violence.

The soldiers and police had deserted for fear of being killed or joined a Christian militia who had opposed Michel Djotodia, the mainly Christian country's first Muslim president who resigned Friday under international pressure.

Christian militiamen attacked a Central African army base in the capital Bangui Tuesday, as French and African soldiers struggled to contain sectarian violence.

Vigilantes attacked a military position at the PK-11 crossroads on the northern outskirts of Bangui, General Mahamat Tahir Zaroga told Agence France Presse.

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.

Around a dozen French tanks deployed Wednesday at Bangui's airport as intense gunfire in adjoining neighborhoods sowed panic among residents.

The tanks took positions at the entrance to the airport, where French and African peacekeepers are based, after automatic weapons fire and explosions shook several parts of the city.

Three ex-rebels shot dead by French troops in the capital of the Central African Republic on Sunday were members of the presidential guard and were "killed in cold blood," the CAR presidency said.

"They were killed in cold blood by members of Sangaris," presidential spokesman Guy Simplice Kodegue said on Monday, referring to the French force sent this month to disarm ex-rebels sowing chaos in the country.

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.

Several thousand Muslim supporters of the Central African Republic's former rebel group Seleka protested Sunday against French troops conducting a disarmament operation.

The demonstration in the capital Bangui marked the most significant show of hostility towards France since it deployed troops on December 5 to end the chaos that followed Seleka's coup in March.

A U.S. operation to airlift some 850 Burundians into the Central African Republic to help restore security to the strife-torn nation should be completed this week, a top U.S. official said Tuesday.

Washington also welcomed Belgian plans to send up to 150 troops to join a French and African Union (AU) force, and revealed that it had a few American troops on the ground in Bangui to help with the airlift.

French President Francois Hollande was expected Tuesday in the Central African Republic, on the second day of an operation to disarm rogue rebels that has already killed two French soldiers.

As the poverty-stricken country's former colonial master led the military effort to restore order after a year of chaos, Washington said it was offering to fly in African peacekeepers.

Clashes between ex-rebels and armed civilians killed six people in Bangui as anger mounted over abuses by the Central African Republic's new rulers, police and medics said Saturday.

The violence broke out on Friday in a northern neighborhood of the capital when a student believed to have been kidnapped by ex-rebels was found dead, a police official said on condition of anonymity.