The UN says it has begun a massive polio vaccination campaign in Afghanistan's troubled southern provinces of Kandahar and Helmand.
Afghanistan is one of four countries where polio has not been eradicated
Taleban leaders have pledged to honour a deal to allow 10,000 health workers to immunise 1.3 million children during the week-long campaign, the UN says.
Afghanistan is one of only four countries in the world where polio has not yet been eradicated.
Last year there were 29 cases of polio in Afghanistan - mostly in the south.
Health workers have been abducted in Afghanistan in the past and the insurgency has often prevented the building of hospitals and clinics.
However, a Taleban spokesman said the workers would be granted safe passage in southern Afghanistan to carry out their programme.
"So far we have not had any reports of any incidents," said Catherine Mbengue, a Unicef spokeswoman in Kandahar.
For more than a year there had been no access to parts of Helmand province, which has seen some of the heaviest fighting between the Taleban and international forces.
"This is an incredible, happy development," said Ms Mbengue.