Thousands of children under the age of five across the eastern province of Kunar couldn't be vaccinated due to insecurity, health officials said.
Farooq Sahak, head of Kunar's central hospital, said 20-25,000 children were not vaccinated because workers are unable to carry out the polio campaigns in areas where the government's control remains contested.
But the provincial governor contradicted Mr. Sahak's assertion about insecurity and said snowfall was the main reason behind the vaccination impediments.
"The health department started the vaccine programme at a time when there was snowfall, and I also think that the figures they provided are inaccurate," said Governor Sayed Fazlullah Wahidi.
Afghanistan, along with Pakistan and Nigeria, are the only countries where polio remains endemic.