"His condition was extremely critical. He died early morning," a senior doctor at a government hospital in Chandigarh told AFP on condition of anonymity.[break]
Sanaullah Ranjay suffered massive head injuries in a prison in the northern city of Jammu, in an attack shortly after the death of an Indian prisoner, Sarabjit Singh, who was assaulted in a Pakistan jail.
Ranjay, who was admitted to the Chandigarh hospital in a serious condition, had suffered renal failure late Wednesday, the doctor said.
The hospital would hand over the body to two of his relatives who had arrived in India on Tuesday "as per the instructions of the government", the doctor added.
Ranjay, a convicted murderer from the Pakistani city of Sialkot, was attacked by a prisoner identified as a former Indian army soldier just 24 hours after Singh´s death in a Lahore jail.
Last weekend demonstrators took to the streets in Pakistan-administered Kashmir to protest against the attack on Ranjay.
The prison violence could fuel tensions between nuclear-armed India and Pakistan, whose relations were hit by a border flare-up earlier this year.
The neighbours have fought two of their three wars over the disputed region of Kashmir, which they each control in part but claim in full.
New Delhi says 535 Indian prisoners, including 483 fishermen, are in Pakistani jails, while 272 Pakistani prisoners are behind bars in India.
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