Koffi Koffi said they could not respond sooner because it would take time to gather equipment and prepare the forces.

An Ivorian Cabinet official who was briefed on the matter said President Alasanne Ouattara requested helicopter gunships from the U.N. and expected them to arrive by Monday. The official spoke on condition of anonymity due to the sensitivity of the matter.

Bert Koenders, the U.N. envoy to the west African nation, said the peacekeepers were part of a patrol south of the town of Tai, an area the U.N. mission recently reinforced because of threats of attacks against the civilian population. The ambush involved a large group of armed men, a U.N. official said, speaking on condition of anonymity because he was not authorized to speak publicly.

"Their colleagues are still in danger," Ban told reporters. "Even tonight, after the attack, more than 40 peacekeepers remain with the villagers in this remote region to protect them from this armed group."