The U.N. Security Council voiced alarm on Friday at an advance by rebels in Central African Republic that has brought them within striking distance of the mineral-rich nation's capital, and renewed its call for a negotiated solution to the crisis.

Central African Republic President Francois Bozize will refuse to leave power during talks with the Seleka rebel alliance, his spokesman said on Thursday, rejecting the insurgents' main demand and raising the prospect of a return to fighting.

The rebel alliance, which has accused Bozize of reneging on a past peace deal, closed in on the capital Bangui this week before bowing to international pressure to start negotiations.

"The members of the Security Council expressed their concern regarding the 'Seleka' coalition's advance toward Bangui since ... December 27," the council said in a statement.

The 15-nation body also urged "an end to Seleka's military offensive, and said the current situation in CAR cannot be resolved militarily."

"They called again on all parties to seek a peaceful solution by engaging constructively, without preconditions, and in good faith in the negotiations to be held in Libreville beginning January 8 under the auspices of the Economic Community of the Central African States (ECCAS)," the council said.

The advance by Seleka, an alliance of five armed groups, was the latest in a series of revolts in a country at the heart of one of Africa's most turbulent regions. The country remains plagued by poverty and underdevelopment despite its reserves of diamonds, gold and other minerals.

The council also repeated its previous demands that Seleka "cease all hostilities, withdraw from seized cities, and cease attempts to advance further."

It voiced concern about "reports of the targeting of ethnic minorities, arrests, detentions, looting, as well as recruitment and use of children in armed conflict in CAR."

The Security Council urged "all parties to refrain from any acts of violence against civilians and to respect human rights, and emphasized that those responsible for such violations should be held accountable," according to the statement.