addis ababa clash along border ethiopia oromiya somali regions displace around 50,000 people senior regional official say sunday violence prompt government send military spokesmen two regions tell regional news outlets early week least 50 people kill side blame lema megersa president oromiya province tell local journalists sunday deaths occur 50,000 people displace home responsible also hold account add give death toll area plague sporadic clash decades referendum hold 2004 determine status dispute settlements fail ease tensions unrest 2015 2016 oromiya less extent regions kill 669 people accord parliament-mandated investigation clash likely fuel fear security ethiopia region big economy staunch western ally side give contradictory explanations cause clash officials oromiya say spark kill local district head raid paramilitary force somali region officials somali region deny claim fifty ethnic somalis kill town aweday oromiya tuesday spokesman somali region tell local media friday international media permit brief sunday prime minister hailemariam desalegn say soldier deploy region quell violence would disarm residents safeguard highways straddle regions week clash eastern ethiopia kill 50 displace 50,000 officials