Rebels, after seizing the Central African Republic's capital of Bangui and forcing President Francois Bozize to flee the country, declared the nation "opened a new page in its history, CNN reported.
For weeks, the Seleka coalition pushed toward Bangui, seizing towns along the way, until it reached the capital city on Sunday.
Witnesses said fierce gunfire lasted for hours. A government official said seven civilians were killed, CNN reported.
By the end of the day, Bozize fled to the Democratic Republic of Congo, government spokesman Jules Gautier Ngbapo said.
A statement issued by Justin Kombo Moustapha, secretary-general of the rebel alliance, said: "The Central African Republic has just opened a new page in its history."
In South Africa, President Jacob Zuma said Monday 13 South African National Defense troops were killed in Sunday's clashes with Seleka rebels in several locations in Bangui.
Zuma said one South African soldier was unaccounted-for and another 27 were injured during the fighting, the Johannesburg Mail and Guardian reported.
"It is a sad moment for our country. We are truly proud of our soldiers -- about 200 of our men fought a force of more than 1,000 bandits for 9 hours," Zuma said in Pretoria. "Our soldiers inflicted heavy casualties on the attacking bandit force. We commend them for their bravery and this will not deter us from going ahead with defending peace and democracy."