Rebel forces in the Central African Republic say they have halted their offensive on the capital, Bangui, and will take part in peace talks.
The announcement from the Seleka rebels comes as the country's neighbours say they are sending in extra troops.
Gabon deployed 120 troops on Tuesday and Cameroon was expected to send a similar number.
The CAR's President, Francois Bozize, has sacked the defence minister - who is his son - and the army chief.
The dismissal of Francis Bozize and Gen Guillaume Lapo was announced on state radio. No reason was given but the president has criticised the army for failing to stop the rebels.
President Bozize has taken over as defence minister, officials said.
Since the Seleka rebels began their campaign a month ago, they have taken several key towns and cities, including the diamond centre of Bria.
On Saturday, they captured Sibut city, which is about 150km (95 miles) from the capital, Bangui, after government forces withdrew.
It is the biggest threat President Bozize has faced since he took power in a coup in 2003.
Both the US and France, the former colonial power, have rejected a plea by the government for help to defeat the rebels.
However, neighbouring states agreed to bolster the Central African Multinational Force (Fomac), which was deployed to the CAR in 2008 to help end years of unrest.'Fled to the bush'
Speaking to BBC Afrique before news of his dismissal, Francis Bozize said Fomac troops had been deployed to Damara, 75km (48 miles) from the capital.
Fomac commander General Jean-Felix Akaga warned the rebels against any attempt to take Damara, the last strategic town between them and Bangui, AFP news agency reports.
"We will not give up Damara," he was quoted as saying.
Damara resident Bertin Andjipassera told Reuters news agency that people have been fleeing their homes.
"Everybody in Damara has gone into the bush, even our wives, our children are in the bush... The hospitals are not working.... There's nothing, just suffering."
Francis Bozize said 120 Gabonese soldiers had arrived in the CAR on Tuesday to bolster the regional force.
A similar number of troops from Cameroon were expected on Wednesday, and they would be followed by a contingent from Congo-Brazzaville, he added.
BBC West Africa correspondent Thomas Fessy says the rebels' capacity to take on these reinforcements is not known and the regional military build-up may well have worked as a deterrent.
Last month, France sent more than 100 paratroopers but insisted they were only there to secure its nationals - not to save the government.
Seleka spokesman Eric Massi told journalists the rebels had been ordered to halt their advance.
"I have asked our forces not to move their positions starting today because we want to enter talks in [Gabon's capital] Libreville for a political solution," he told Reuters on Wednesday.
"I am in discussion with our partners to come up with proposals to end the crisis, but one solution could be a political transition that excludes [President] Bozize."
A regional body, the Economic Community of Central African States (Eccas), is trying to arrange talks between the government and rebels in Libreville, while strengthening its force in the CAR.
Seleka - an alliance of three separate groups - accuses the government of failing to honour a 2007 peace deal under which fighters who laid down their arms were meant to be paid.
They have dismissed the president's offer to form a national unity government.