Thirty children have died at a hospital in India's northern state of Uttar Pradesh since Wednesday due to encephalitis and delivery-related issues, a senior medical official said on Friday.

Chief Medical Superintendent Dr R.S. Shukla also denied accusations made by a district official in local media that the deaths were due to an oxygen shortage he said occurred after a private supplier withdrew its equipment over unpaid hospital dues.

The dead children ranged from babies to 12-year-olds.

Shukla said at least 10 of the children at BRD Medical College had died because of encephalitis, a disease that causes inflammation of the brain, while the rest had died from "delivery-related issues", without providing further details.

Other officials at the hospital were not immediately reachable.

Uttar Pradesh officials are conducting an investigation of the matter, said a senior state government official.