Attacks by non-State armed groups in parts of north-east Nigeria have left relief workers unsure about the extent of needs among some communities, the UN migration agency’s top official in the country said on Tuesday.

Chief of Mission of the International Organization for Migration (IOM), Frantz Celestin, told UN News’s Daniel Johnson about the extremists’ use of “hit-and-run” tactics, and explained what the priorities are now for the aid teams coping with mass displacement and overcrowded protection camps.