France on Sunday said it was deploying 350 soldiers to ensure the security of French nationals and other foreigners after rebels took over the capital city.
The contingent arrived in the country on Saturday, with the rest dispatched on Sunday.
The actions by Paris come after President Francois Bozize - the target of an attempt to overthrow the government by Central African Republic rebels - fled to Congo on Sunday.
"The rebels control the town," presidential spokesman Gaston Mackouzangba said. "I hope there will not be any reprisals."
Witnesses reported gunfire and explosions in the city, and one rebel commander told the AFP news agency that the presidential palace had been taken in Bangui.
"We have taken the presidential palace," said Colonel Djouma Narkoyo, a commander on the ground. "Bozize was not there."
Since Friday, several towns have fallen after a peace accord between the rebels and the government collapsed. The rebels are made up of several opposition groups, officially known as the Seleka coalition.
French President Francois Hollande noted Bozize’s departure on Sunday and asked "the armed groups to respect the population.”
The rebel groups first seized the town of Bossangoa, which lies in the west of the country. They later took Damara, where the ceasefire boundary line had been drawn.
The Seleka rebels have faced little resistance from the army, which is ill-trained and ill-equipped.
The UN Security Council has reacted to the unraveling situation with alarm. On Friday, the 15-nation body met to discuss the escalation of hostilities. They later released a press statement warning the rebels that they would face consequences for any human rights violations in areas under their control.
rc, mz/pfd (AFP, AP, Reuters)