Supporters of Central African Republic President Francois Bozize have set up roadblocks in the capital, Bangui, saying they want to stop any rebel incursion.
French media reports say young men describing themselves as "patriots" are manning checkpoints where they stop vehicles and question occupants in a search for rebel fighters.
The rebel coalition known as Seleka has taken several major towns and cities, including one less than 200 kilometers from the capital.
Reuters news agency quotes a rebel spokesman, Eric Massi, as saying Seleka has halted its advance because the rebels want to open talks with the government.
Central African leaders are trying to organize peace talks that would take place in Gabon on January 10.
The regional leaders have warned the rebels against taking the town of Damara, just 75 kilometers north of Bangui.
Meantime, Chad, the Republic of Congo and Gabon have sent troops to Bangui to protect the capital and back up the C.A.R.'s national army.
President Bozize has led the Central African Republic since seizing power in a 2003 coup.
Some information for this report was provided by AFP and Reuters.