(CNN) -- Islamic militants ambushed Ethiopian forces in southern Somalia Saturday and hours-long fighting left scores of people dead.
The fierce firefights killed 86 Al-Shabaab fighters, said Diyad Abdi Kalil, a commander of the transitional government in Somalia's Gedo province. The militants ambushed the soldiers in the town of Yurkut, still under Somali control.
In recent weeks, Somali government forces, backed by their Ethiopian allies, have retaken southern towns controlled by Al-Shabaab, including strategically important Baidoa.
The gun battles lasted almost five hours, Kalil said, and erupted a day after the African Union announced that Ethiopia planned to withdraw its troops from Somalia by the end of April.
Paddy Ankunda, spokesman for the African Union Mission in Somalia (AMISOM) said forces from Djibouti, Uganda and Burundi will replace the Ethiopians.
Meanwhile, Sheikh Abu Musab, the military spokesman of Al-Shabaab claimed on a local radio station that its fighters killed 73 soldiers, mostly Ethiopians, in Saturday's fighting.
The Islamist group has waged an insurgency against the feeble Transitional Federal Government since 2007 but is now on the defensive in its heartland in southern Somalia.
It announced last month that it was tightening its ties to al Qaeda and has long been considered a terrorist movement by the United States.
AMISOM and government forces drove Al-Shabaab fighters from the center of the Somali capital Mogadishu last year, while Kenyan troops crossed into southern Somalia in October to hit back for a rash of kidnappings it blamed on the group.
That Kenyan operation is ongoing. After it began, Ethiopian troops joined Somali government units in attacking Al-Shabaab strongholds.