Members of the rebel Seleka alliance signed a peace agreement with the government in January. The United Nations reports that rebel fighters have expressed frustration with the government's commitment, however, and have since captured key cities.
Margaret Vogt, a special envoy for U.N. Secretary-General Ban Ki-moon, said the Security Council was growing alarmed by the renewed fighting in CAR.
"The members of the Security Council expressed strong concern at the deterioration of the security situation in the Central African Republic," she said in a statement. "They condemned the attacks conducted recently by rebels from the Seleka coalition, in particular in Bangassou (in southern CAR) and the surrounding region, and the threat of a resumption of hostilities."
She welcomed the appointment of Nicolas Tiangaye as prime minister of CAR, saying he is the leader of a government of national unity under the terms of the January measure.
The United Nations estimates at least 80,000 people were displaced by CAR fighting. The rebel campaign was meant to pressure President Francois Bozize to step aside.