Officials in the Afghan town of Musa Qala say nearly 30 children there have died from measles since the Taleban were forced out of the town last month.
They say the disease has been exacerbated by cold weather.
Doctors say many of the children were from families displaced by the fighting, who were unable to find adequate shelter.
Musa Qala, in Helmand province, was recaptured by Nato and Afghan troops in a combined air and ground offensive.
Medical officials in the Helmand capital, Lashkar Gah, said they were unaware of the problems in Musa Qala.