A children’s advocacy group is warning of a spike in cholera cases in northern Yemen affecting hundreds of thousands of children and their families as a result of an increase in fuel shortages.

Save the Children said Wednesday that fuel shortages have resulted in a jump in food prices and, as a result, a deepening health crisis.

The group says fuel prices have hiked 100% over the past 40 days as the internationally recognized government imposed customs duties in the interim capital Aden. That caused a 60% decrease in the amount of fuel coming through the key port of Hodeida, the group says.

Save the Children says the resulting health crisis has led to a mounting risk of more cases of cholera and other waterborne diseases.

Yemen already has a cholera problem, with over 620,348 suspected cases identified this year.