Bangui - Rebels waging an offensive in the Central African Republic seized another major town on Tuesday, a military source said, bringing them a step closer to the nation's capital.
The rebel coalition known as Seleka, an alliance of three groups, reached Kaga-Bandoro, the fourth regional capital they have captured during their offensive that began on December 10.
While one of the rebel leaders has said they do not want to march on the capital, the fighters have nevertheless made a rapid advance south and west towards the capital, meeting little resistance from government troops.
However a Central African military source told AFP late on Tuesday that a contingent of Chadian troops invited into the country by Central Africa's President Francois Bozize were moving north from Sibut towards Kaga-Bandoro.
Sibut lies roughly equidistant between the capital Bangui, further south, and Kaga-Bandoro.
"Chadian soldiers have their base in Sibut, but several hours ago, a part of the contingent took the road for Kaga Bandoro, but we don't know for what reason," said the source.
It is not clear how many soldiers Chad has sent into the Central African Republic, its southern neighbour. Chad's forces previously helped Bozize during rebellions in the north in 2010.
Last week Chad offered to mediate between the two sides and has said its troops are a peacekeeping force. Thus far, they have not opposed the rebels' swift advance.
Earlier on Tuesday, a military source in Bangui said Bozize had met with military officers to discuss the situation.
Rebels arrived in the market town Kaga-Bandoro "in vehicles and on motorcycles, and started using heavy weapons to fire at strategic points: a military base, police stations, the customs office," said a military source in Sibut, about 130km south.
"Members of the Central African armed forces resisted briefly then began to retreat towards Sibut," he added. Sibut itself lies around 100km from Bangui.
"A large part of the population took cover in their homes when they heard the explosions, and many residents fled in the direction of neighbouring villages," the Sibut military source added.
Kago-Bandoro is the fourth regional capital to be captured by rebels after Ndele in the north; Bria in the central region of Haute-Kotto; and Bambari, further to the southwest.
They now control large swathes of the north and the east of the country and are moving ever closer to Bangui, which sits on the border with the Democratic Republic of the Congo and also lies near the Republic of the Congo.
The Central African army is ill-equipped, under-paid and poorly organised and has offered scant resistance to the rebels. Government troops surrendered their stronghold in Bambari, in the south-central Ouaka region, in just a few hours on Sunday.
The rebels want the government to honour peace accords signed between 2007 and 2011 that offered financial support and other help for rebel fighters who laid down their arms.
Despite pressure from the international community, the rebels have refused to halt their operations.
On Friday, Bozize and other central African leaders meeting in the Chadian capital N'Djamena proposed talks.
The same day, one rebel leader said they were suspending their advance to give such talks a chance. A day later however, another of the rebel alliance's leader had announced the capture of two more towns.
In Bangui, the government said Monday it would only hold talks if the rebels pulled back from the towns they had captured. The rebels said Monday they were still open to talks, provided Bozize announced a ceasefire first.
Bozize himself seized power in a coup in 2003.
The Central African Republic is a mineral-rich, landlocked country with less than five million residents. It ranks 179 out of 187 countries on the UN's latest development index and has seen frequent coups and mutinies.