addis ababa somali authorities hand ethiopia senior official onlf rebel group fight secession ogaden ethiopia group say abdikarin sheikh muse executive committee member live somali capital mogadishu detain security galkayo somalia semi-autonomous galmudug state august 23 onlf say statement quote source close somali cabinet say somali government forcefully hand abdikarin sheikh muse ethiopia without consent violation u.n. convention relate status refugees ethiopian officials available comment ogaden national liberation front onlf launch bid secession somali region also know ogaden eastern ethiopia 1984 2007 ethiopian force wag large-scale offensive group attack chinese-run oil facility kill 74 people analysts say rebel since severely weaken still able launch hit-and-run attack region operate may contain trillion cubic feet gas major oil deposit mine experts say china gcl-poly petroleum investments sign production share deal government late 2013 develop two gas field somalia hand onlf rebel leader ethiopia group