The UNICEF representative for Sudan warned that polio may outbreak in Blue Nile, Nuba Mountains, and Jebel Marra in Darfur because more than 200,000 children under five have not received vaccination for the past four years.

Geert Cappelaere said 23 October was World Polio Day and 99.9 percent of the work to eradicate polio worldwide is done, but a significant part of the remaining work is in Sudan.

Without the vaccination, there was a chance of emergence of polio very soon, he warned.

Cappelaere said no reports of polio outbreaks had been reported this year, but a massive measles outbreak had affected the areas in 2015.

Cappelaere said the three areas have not been accessible by aid groups due to conflict, noting Sudan is host to one of the largest humanitarian crises on Earth today with more than three million children suffering.

The child welfare activist called on government and rebel forces to stop fighting. He said commitments to end the violence have not been translated into action.