NEW : Though these two men have since been cleared , the incident underscores a need for governments to do better checking passenger lists , he said . The search is ` ` the most difficult in human history , '' Australia 's Abbott says . ` ` We will not rest until they are indeed found , '' Malaysian PM says . Australian ambassador : Focus moves due to searchers ` ` populated areas '' Official : All 227 passengers have been cleared of hijacking , psych ##osis .
NEW : The search is ` ` the most difficult in human history , '' Australia 's Abbott says . ` ` We will not rest until they are indeed found , '' Malaysian PM says . Australian ambassador : Focus moves due to searchers ` ` populated areas '' Official : All 227 passengers have been cleared of hijacking , psych ##osis .