On this edition of Africa 54, at least three people are shot in northern Nigeria as violence breaks out amid the return of 279 kidnapped schoolgirls to their families; United Nations human rights chief calls on Ethiopia to grant United Nations monitors access to the Tigray region to investigate reports of continuing killings and sexual violence that may amount to war crimes; Senegal's main opposition leader is arrested after hundreds of his supporters clashed with police in the capital while protesting against a rape accusation he denies.