A Pakistani prisoner who was attacked by a fellow inmate at a high-security prison in Indian-administered Kashmir has died in hospital, doctors say.

Sanaullah Ranjay, who was in a coma, died of multi-organ failure at a hospital in India's Chandigarh city early on Thursday.

India said it would return his body to Pakistan. Islamabad called for an international probe into his death.

Sanjoy Majumder reports.