▁the ▁con ferences ▁on ▁Niger ian ▁Constitution ▁and ▁Independ ence . ▁ ▁Post - colon ial ▁period ▁In ▁ 1 9 6 1 , ▁another ▁major ▁crisis ▁occurred ▁when ▁the ▁then ▁eastern ▁region ▁of ▁Niger ia ▁allowed ▁present - day ▁South western ▁Cam ero on ▁to ▁separate ▁from ▁Niger ia ▁( from ▁the ▁region ▁of ▁what ▁is ▁now ▁Ak wa ▁Ib om ▁and ▁Cross ▁River ▁states ) ▁through ▁a ▁ple bis cite ▁while ▁the ▁leadership ▁of ▁the ▁then ▁Northern ▁Region ▁took ▁the ▁necessary ▁steps ▁to ▁keep ▁North western ▁Cam ero on ▁in ▁Niger ia , ▁in ▁present - day ▁Adam awa ▁and ▁Tar aba ▁states . ▁The ▁after math ▁of ▁the ▁ 1 9 6 1 ▁ple bis cite ▁has ▁led ▁to ▁a ▁dispute ▁between ▁Cam ero on ▁and ▁Niger ia ▁over ▁the ▁small ▁territory ▁of ▁Bak ass i . ▁ ▁A ▁new ▁phase ▁of ▁the ▁struggle ▁saw ▁the ▁declaration ▁of ▁an ▁Independent ▁Niger ▁D elta ▁Republic ▁by ▁Isaac ▁Ad aka ▁B oro ▁during ▁Niger ian ▁president ▁Ir ons i ' s ▁administration , ▁just ▁before ▁the ▁Niger ian ▁Civil ▁War . ▁ ▁Also ▁just ▁before ▁the ▁Niger ian ▁civil ▁war , ▁S out he astern ▁State ▁of ▁Niger ia ▁was ▁created ▁( also ▁known ▁as ▁S out he astern ▁Niger ia ▁or ▁Coast al ▁S out he astern ▁Niger ia ), ▁which ▁had ▁the ▁colonial ▁Cal ab ar ▁division , ▁and ▁colonial ▁O go ja ▁division . ▁R ivers ▁State ▁was ▁also ▁created . ▁S out he astern ▁state ▁and ▁River ▁state