CAIRO — 

At least 10 child leukemia patients in Yemen have died, and dozens more were left seriously ill, after being administered expired doses of a cancer treatment in the rebel-held capital, medical officials and workers said Friday.

Yemen's ruinous conflict, now entering its eighth year, has caused one of the world's worst humanitarian crises and killed in excess of 150,000 people.

The children were between the ages of 3 and 15 and died at Sanaa's Kuwait Hospital after being injected with old doses of smuggled medicine at a number of private clinics, the rebel-run Health Ministry said in a statement Thursday. The officials did not say when the 10 deaths occurred.

According to a half-dozen health officials and workers who spoke to The Associated Press, about 50 children received a smuggled chemotherapy treatment known as methotrexate that was originally manufactured in India. They said a total of 19 children had died from the expired treatment. The officials and workers spoke on condition of anonymity as they were not briefed to speak with the media.

Amid Yemen's war, the lack of access to basic resources, including food and medicine, has created large smuggling networks across both rebel-held Houthi and Saudi coalition-run areas.