Addis Ababa - Ethiopia on Friday said a senior figure with the rebel Ogaden National Liberation Front has willingly surrendered, days after the group accused neighboring Somalia's security forces of kidnapping and forcibly extraditing him.Ethiopia foreign ministry spokesman Meles Alem told The Associated Press that Somalia "played a facilitation role" in the surrender of Abdikarin Sheikh Muse.The incident involving the ethnic Somali rebel leader has sparked outrage in Somalia, with some accusing the government of violating the constitution, which bars the extradition of Somali citizens to another country. Somalia's government has not confirmed the extradition, and the intelligence chief has called it a "sensitive matter."It is not clear what nationality Muse holds. The Ethiopian ministry spokesman said he has Ethiopian citizenship.The ONLF rebels seek the secession of Ethiopia's ethnic Somali region and have waged an armed struggle against the government. Ethiopian lawmakers in 2011 labeled the ONLF a terror group alongside al-Qaida and al-Shabab. No senior member of ONLF had been detained in recent years.In a statement issued on Wednesday, the rebel group said Abdikarin was arrested in the Somalia town of Galkayo, where he went to bring his young niece to the capital, Mogadishu, for medical treatment."The Somali government refused to let relatives of Abdikarin Sheikh Muse to visit him while claiming that they will release him soon," the statement said. "The Somali government has ignored their pleas and has forcefully handed over Abdikarin Sheikh Muse without his consent to Ethiopia."Ethiopia recently sent several hundred Somali detainees back to Somalia, most of them members of al-Shabab.