Four hospitals failed to report suspected cases of polio in a far northwestern region of China that experienced an outbreak of the disease in August, the regional government said Tuesday .

During the epidemic monitoring period, the hospitals, located in four cities in the Xinjiang Uyghur Autonomous Region, including the regional capital Urumqi and the border town Kashgar, failed to report 23 cases of Acute Flaccid Paralysis (AFP), a common indicator of polio, said the regional government's health bureau.

Twenty persons have been infected since a polio epidemic started in Xinjiang in August. The local government has conducted large-scale vaccinations across the region.

Poliomyelitis, or polio, is a viral disease of the brain and spinal cord that mainly affects children under five years old.

Four regions in Xinjiang - the prefectures of Hotan, Kashgar, Bayingolin and Aksu - were classified as epidemic zones.

Xinhua