Nearly 6,500 children were found to be severely malnourished last year at camps set up for people made homeless by Boko Haram insurgents, health officials in northeast Nigeria said on Monday.
"We recorded about 6,444 severe cases of malnutrition in the IDP (internally displaced persons) camps during the period," said the head of the Borno State Primary Health Care Board, Sule Mele.
"25,511 others have mild to moderate symptoms, while 177,622 among the children were not malnourished," he told reporters.
More than 2.6 million people have been forced to flee the violence in northeast Nigeria since Boko Haram began its violent campaign to create a hardline Islamic state in 2009.
At least 17,000 people have been killed in the same period.
The figures lay bare the effects of the insurgency, with farming virtually impossible in the mainly agricultural region and delivery of food supplies made difficult because of the unrest.
Aid agencies have long warned about a worsening humanitarian crisis in the region because of the vast numbers of displaced and the pressure on local authorities forced to host them.
Nigeria's government, which maintains it has "technically" defeated Boko Haram, is pushing a policy of returning IDPs to their homes, despite continued sporadic attacks.
But IDPs at one of the camps in Maiduguri told AFP earlier this month they were reluctant to return, citing lack of security, food and clean water.
Education and healthcare have also been severely hit by the fighting.
Mele said the deaths of some 459 children aged one to five in camps last year from preventable childhood diseases such as diarrhoea, vomiting and measles were exacerbated by malnutrition.
Children were not getting the required nutrition from food distributed at the camps, affecting health, growth and physical development, as well as increasing susceptibility to disease.
"Even if the children get enough to eat, they will become malnourished if the food they eat does not provide the proper amounts of micro-nutrients, vitamins and minerals to meet daily nutritional requirements," he added.
Children with severe acute malnutrition were receiving treatment with help from non-governmental organisations but more needed to be done to reduce the problem, Sule said.