The United Nations says workers in humanitarian convoys have discovered cases of acute malnutrition and famine-like conditions in northern Nigeria's Borno state, particularly in 15 camps where some 275,000 displaced people are living.

A U.N. Office for the Coordination of Humanitarian Affairs report released Tuesday says the camps are in hard-to-reach, insecure areas, many of them where there is active fighting as a result of Boko Haram's 6-year Islamic insurgency. The report does not say how many cases of malnutrition were found.

The U.N has said about 3.8 million people in the area around Lake Chad that includes northern Nigeria and parts of Cameroon, Chad and Niger lack reliable access to enough affordable, nutritious food. The region has suffered from both military conflict and environmental degradation.