Ivory Coast government warplanes carried out two attacks against the northern rebel stronghold of Bouake Thursday, threatening to return the nation to war.
Several people were reported injured in the air strikes.
A rebel commander described the bombing raids as "a declaration of war."
Ivorian military commanders say the attacks are designed to reconquer territory held by New Forces rebels since 2002, when a coup attempt sparked a civil war.
United Nations officials in Ivory Coast are holding an emergency meeting and have refused to comment on the air strikes.
Although the civil war was declared over last year and a peace deal was signed, Ivory Coast remains tense and divided between the government-controlled south and the rebel-held north.
Just last month, rebel forces refused to begin disarming as scheduled, saying President Laurent Gbagbo has refused to implement political reforms.