Rohingya rebels attacked an army truck in Myanmar's restive Rakhine state and wounded five soldiers, state media said.
A spokesman for the Arakan Rohingya Salvation Army (ARSA) claimed responsibility for the ambush on Friday.
"A vehicle ... was attacked by 20 insurgents from the mountain using homemade mines and small arms," the government said, adding about 10 rebels were involved.
The military added "extremist Bengali terrorists ARSA" carried out the ambush.
A series of attacks on security installations last August ignited an exodus of more than 620,000 Rohingya villagers from Rakhine into neighbouring Bangladesh, after Myanmar soldiers launched a brutal crackdown.
Fleeing Rohingya have reported many stories of mass killings, gang rape, and arson attacks by security forces.
The United Nations has called violence against civilians "ethnic cleansing", but Myanmar's government has rejected the description.
A rebel spokesman confirmed his group had carried out the attack. "Yes, ARSA takes responsibility for the latest military movement," the unidentified fighter told Reuters news agency.
Yangon-based Frontier Myanmar magazine reported six soldiers were hospitalised, one with critical wounds.