Three soldiers were killed and seven wounded when two military posts in northern Ivory Coast were attacked early on Monday, five senior military sources said.
Two assailants were also killed and four others were detained, the sources said.
There was no immediate claim of responsibility for the attacks. An Ivorian army source said the attackers had been identified as from neighbouring Burkina Faso, but this could not be confirmed.
The military sources said two soldiers were killed in a raid on a military camp in Kafolo near the border with Burkina Faso. An officer stationed at another post in nearby Tehini was killed as the assailants fled the scene, they said.
Weapons and other military equipment were seized in the raids, and Ivorian troops were carrying out a search operation in the area, one of the senior military sources said.
Thirteen soldiers were killed when the Kafolo military outpost was ambushed last year. The defence ministry blamed the attack on jihadists, and dozens of suspected militants were arrested.
Armed militant groups linked to al Qaeda and the Islamic State present in Ivory Coast's northern neighbours Mali and Burkina Faso have made incursions in southern coastal states, raising fears the instability could spread further south.