Central African Republic's President Francois Bozizé fled the capital early Sunday, hours after hundreds of armed rebels threatening to overthrow him invaded the city of Bangui, an adviser said.

The rebel alliance, known as Seleka, issued a statement referring to Bozizé as the country's "former president."

"Central African Republic has just opened a new page in its history," said the communiqué, which was signed by Justin Kombo Moustapha, secretary-general of Seleka.

"The political committee of the Seleka coalition, made up of Central Africans of all kinds, calls on the population to remain calm and to prepare to welcome the revolutionary forces of Seleka," it said.

Presidential palace seized

The rebels had reached the outskirts of Bangui late Saturday. Heavy gunfire echoed through the city Sunday as the fighters made their way into the heart of downtown and seized the presidential palace, though the country's leader of a decade was not there at the time.

"Bozizé left the city this morning," said Maximin Olouamat, a member of Bozizé's presidential majority. The adviser declined to say where the president had gone.

Coverseas Worldwide Assistance, a Swiss-based crisis management firm that has contacts on the ground, said it believed Bozizé was headed toward neighbouring Congo.

Widespread looting reported

Both rebels and residents of the capital are accused of widespread looting and there are reports that Seleka-allied rebels ransacked the home of Bozizé's son in Bangui.

The city is located along the Oubangui River that separates the two countries.

Congolese government spokesman Lambert Mende, however, said he had no knowledge of Bozizé crossing into Congo.

Rebels from several armed groups that have long opposed Bozizé joined forces in December and began seizing towns across the country's sparsely populated north. They threatened at the time to march on Bangui, but ultimately halted their advance and agreed to go to peace negotiations in Libreville, the capital of Gabon.

A peace deal was signed Jan. 11 that allowed Bozizé to finish his term that expires in 2016, but the rebels soon began accusing the president of failing to fulfil the promises that were made.

Deal unraveled

They demanded that Bozizé send home South African forces who were helping bolster the country's military. And they sought to integrate some 2,000 rebel fighters into Central African Republic's armed forces.

The deal unraveled more than a week ago, with the rebels again taking control of two towns and threatening to advance on the capital.

Late Saturday, Bangui was plunged into darkness after fighters cut power to much of the city. State radio went dead, and fearful residents cowered in their homes.

An unspecified number of French citizens have taken refuge in the French Embassy, a diplomat said on condition of anonymity because he wasn't authorized to be publicly named according to Foreign Ministry policy.

"For us, there is no other solution than the departure of Francois Bozizé," Eric Massi, a rebel spokesman, said from Paris by telephone late Saturday.

Massi said the rebels were securing the city, and he called on residents to remain calm and avoid looting amid the chaos.

South African Brig. Gen. Xolani Mabanga, the country's military spokesman, said there had been "intense" fighting this weekend between the rebels and South African forces.

"Our base was attacked by the rebels as they were advancing toward the capital," he said. South African forces suffered casualties from the fighting Saturday night, he said.

"We have suffered some casualties," he said. He declined to provide the number of casualties, pending the outcome of an investigation.

He said the situation for South African forces was "relatively calm" on Sunday afternoon.

"There are no threats at this moment," he said.

The growing unrest is the latest threat to the stability of Central African Republic, a nation of 4.5 million that has long been wracked by rebellions and power grabs.

The president himself took power in 2003 following a rebellion, and his tenure has been marked by conflict with myriad armed groups.