abuja nigeria arm force say friday group campaign secession part southeastern nigeria formerly know biafra categorize terrorist organization move follow days tension members group accuse army lay siege leader home army deny curfew impose abia state residence locate indigenous people biafra ipob group step call secession since leader nnamdi kanu release bail april detain nearly two years charge criminal conspiracy belong illegal society secessionist sentiment simmer region since biafra separatist rebellion plunge africa populous country civil war 1967-70 kill estimate one million people military presence southeastern nigeria increase last weeks part operation military say part efforts crack crime arm force nigeria wish confirm general public ipob intent plan purpose analyze militant terrorist organization say arm force spokesman john enenche email statement statement say ipob form biafra secret service paramilitary division extort money people public roads attack members arm force ipob spokesman immediately available comment tension another security challenge president muhammadu buhari addition eight-year boko haram jihadist insurgency northeast attempt maintain fragile ceasefire southern niger delta energy hub militant attack oil facilities niger delta last year cut crude production third renew call biafran secession prompt buhari use first speech return three months medical leave britain august say nigeria unity negotiable amid mount tensions region army thursday say investigate video footage circulate social media purportedly show troop checkpoint abia use stick flog men strip waist force drink muddy water amnesty international 2016 accuse nigeria security force kill least 150 biafra separatists peaceful rally military police deny allegations version story correct typo headline nigerian military label biafra separatist group terrorist organization