The Ogaden National Liberation Front (ONLF) army returned to Somali regional state from their base in Eritrea after the Front had reached an agreement with the government of Ethiopia.
Upon arrival at the Jigjiga town, they were welcomed by residents and other senior local officials.
The Government of Ethiopian and ONLF signed a peace deal in the Eritrean capital Asmara last month.
The two sides held a productive discussion and reached a historic deal that allowed the ONLF to undertake peaceful political struggle in Ethiopia, according to a statement from the ministry.
The Ethiopian parliament has also removed ONLF from the terrorist list recently so as to pave ways for peaceful dialogue.
The group based itself in Ethiopia’s neighbouring Eritrea for decades and insisted its armed operations were to defend Somalis in Ethio-Somali region.