Reports say Islamist militant group al-Shabab has ambushed an Ethiopian base in Somalia, with dozens of casualties.
Al-Shabab claimed to have killed 73 Ethiopians, while the Somali government said it in turn killed 48 members of the militant group.
International correspondents say it is the most intense fighting since Ethiopian troops entered Somalia last November.
The fighting lasted for more than three hours, but correspondents say it will be difficult to verify the exact number of dead.
The attack took place between the border with Ethiopia and Somalia.
It came hours after the African Union announced the troops would be withdrawn from towns the Ethiopians took, by the end of April.