A medical aid group says malnutrition among children in eastern Chad has reached “emergency” levels, and is calling for action from Chad's government and humanitarian agencies.

Doctors Without Borders says an assessment last month in Chad's Biltine district found that nearly a quarter of children ages zero to five were either moderately or severely malnourished.

It says the rate is of great concern because February normally features the lowest malnutrition rates of the year. It also said malnutrition rates have risen sharply since the U.N. children's agency surveyed the same area last August and September.

Doctors Without Borders blamed the situation on a below-normal harvest, crop-destroying pests, and a downturn in Chad's economy, because of reduced remittances from Libya.

The group says this week it will launch an emergency nutrition project in Biltine in collaboration with Chad's ministry of health.