The U.N. peacekeeping mission in Ivory Coast, known by its French initials UNOCI, said armed bandits made off with weapons from the armory near a military base in Abidjan. The mission said it sent peacekeepers to the area to help support the Ivorian military.
"The provisional toll of the attack is seven dead and about a dozen seriously injured among the ranks of the (military force)," the mission said in a statement.
Attacks on a camp for the internally displaced last month were said to be ethnically motivated.
Ivory Coast is struggling with national reconciliation efforts nearly two years after disputed presidential elections.
Former President Laurent Ggabgo refused to give up power after the international community recognized rival Alassane Ouattara as the victor in 2010 elections meant to unite a country divided by civil war.
Gbagbo is awaiting trial at the International Criminal Court for war crimes allegedly committed after the election. Human rights groups said both sides likely committed atrocities, however.