The condition of injured Pakistani prisoner Sanaullah has deteriorated further, Indian officials said Wednesday.


“According to doctors, the patient has become extremely critical. He has developed renal failure with no urine output since morning,” said Manju Wadwalkar, the public relations officer of Post Graduate Institute of Medical Education and Research (PGIMER) hospital in Chandigarh of India.


“Neurologically he continues to be in deep coma and his overall status is extremely critical, far worse than last night.”


52-year-old Sanaullah is undergoing treatment in the intensive care unit of PGIMER Hospital in Chandigarh city.


Sanaullah suffered multiple head injuries last week after being attacked by another inmate inside Kot Balwal jail of Indian-occupied Kashmir.


Following the attack he slipped into deep comma and was airlifted to PGIMER Chandigarh, a premier health institute in north India.


The attack on Sanaullah was seen as an apparent retaliation to the death of a convicted Indian spy Sarabjit Singh on Thursday. Singh was assaulted by a fellow prisoner inside a prison in Lahore of Pakistan on April 26.


Indian officials say there are 535 Indian prisoners in Pakistani jails and 272 Pakistani prisoners in Indian jails.


Two relatives of Sanaullah have gone to India to inquire about his health.