Rebels fighting the president of the Central  African Republic, François Bozize, have rejected appeals from the African Union to form a coalition government and to halt their advance on the capital Bangui.

"We are not convinced of the commitments made by President Bozize," said Juma Narkoyo, the rebel spokesman, when reached by telephone by the Associated Press in Bangui on Monday.

"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 AU is trying to secure a lull in fighting, which has seen the rebels take several towns, to encourage them and Bozize to form a unity government.

The rebels' refusal to halt their advance came as dozens of troops from neighbouring  Republic of Congo arrived at sunset on New Year's Eve in Bangui 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 towards the line between government forces and a coalition of four rebel groups known as Seleka north of Bangui.

About 10 towns, including Sibut, which is about 185km from Bangui, are currently in the hands of the rebels who have vowed to advance on the capital.

Curfew imposed

Fighting began less than a month ago and the rebels have taken town after town, sometimes without a shot being fired.

The government imposed a curfew starting from 7pm, leaving the streets largely empty on New Year's Eve.

The rebels claim that Bozize has abducted more than a dozen of their family members and warned if the president uses foreign troops to protect his government, they may continue their military campaign towards the capital.

But the African Union has told the rebels that if they seize power they will face sanctions and Central African Republic will be suspended from the continental bloc.

Meanwhile, Francois Hollande, France's president, welcomed the efforts by the AU and the group of neighbouring states to find a negotiated solution.

Hollande called for "opening a dialogue between CAR authorities and all the parties present, including the rebellion".

Hollande last week said his government would only protect French interests in CAR, but 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 was not fully implemented.

Neighbouring African countries have agreed to send more forces to support Bozize while China and the US have been arranging for their nationals to leave the country.

Source: Agencies