BANGUI, Central African Republic — President Francois Bozize's government came under growing threat Monday as rebels vowing to overthrow him rejected appeals from the African Union to hold their advance and try to form a coalition government.
Meanwhile, dozens of troops from the Republic of Congo arrived at sunset on New Year's Eve in Bangui, the capital, as part of an effort to step up the presence of a multinational regional military force.
After disembarking from their military aircraft, the group of about 120 men headed toward the line between government forces and a coalition of four rebel groups known as Seleka north of Bangui.
The rebels have seized control of about 10 towns in less than a month's time, and now have moved within striking distance of the capital, a city of more than 700,000 people.
The government has imposed a curfew of 7 p.m., leaving the streets largely empty on New Year's Eve.
Soldiers from the Central African Republic and a regional military force are currently in Damara, about 45 miles from Bangui. The rebels, meanwhile, are holding the city of Sibut, which is about 115 miles away.
The rebels said Monday that they did not trust Mr. Bozize's offer to form a unity government, raising fears they could attempt confrontation with government forces in the coming days.
"We are not convinced of the commitments made by President Bozize," rebel spokesman Juma Narkoyo said. "Bozize has always spoken, but he never keeps his word."
The rebels said they would enter negotiations "only if the head of state releases all our relatives they have arrested without reason."
The rebels claim that Mr. Bozize has abducted more than a dozen of their family members. They warned if the president uses foreign troops to protect his government, they may continue their campaign toward the capital.
In response, the rebels were told by the African Union that if they seize power they will face sanctions and the Central African Republic will be suspended from the organization.
Meanwhile, French President Francois Hollande welcomed the efforts by the AU and the group of neighboring states to find a negotiated solution.
Mr. Hollande called for "opening a dialogue between [Central African Republic] authorities and all the parties present, including the rebellion." Last week, Mr. Hollande said his government would protect only French interests in the country and would not prop up the Bozize government.
Central African Republic has suffered many army revolts, coups and rebellions since gaining independence from France in 1960.
The rebels behind the current instability signed a 2007 peace accord allowing them to join the regular army, but insurgent leaders say the deal wasn't fully implemented.
Neighboring African countries have agreed to send more forces to support the Bozize government.
The ongoing instability already has prompted the United States to evacuate about 40 people, including the U.S. ambassador, from Bangui on an Air Force plane bound for Kenya, U.S. officials said on condition of anonymity because they weren't authorized to discuss the operation.
The U.S. has special forces troops in the country who are assisting in the hunt for Joseph Kony, the fugitive leader of another rebel group known as the Lord's Resistance Army.
The evacuation of the U.S. diplomats came after criticism of how the U.S. handled diplomatic security before and during the attack on its consulate in Benghazi, Libya, on Sept. 11. The ambassador and three other Americans were killed in that attack.