His condition is stated to be serious, official sources said.
It was not immediately known whether the attack on the 52-year-old convict with a sharp weapon was a backlash against the death of Indian prisoner Sarabjit Singh in a hospital in Pakistan on Thursday. Prior to his death, Singh had been comatose for nearly a week following a brutal assault by fellow inmates in a high-security Lahore jail, officials said.
Official sources said Kot Balwal Jail Superintendent Rajni Sehgal has been suspended by the Jammu and Kashmir government, which had also ordered a probe.
The sources said Sanaullah, a resident of Pakistan, was admitted in Government Medical College hospital in an unconscious condition with serious injuries on his head after being hit with a garden hoe by a prisoner from Uttaranchal, Vinod Kumar, after the duo had a heated exchange.
Sanuallah, a resident of Sialkot in Pakistan, was later rushed to PGI Chandigarh in an air ambulance, after doctors said his condition was critical.
A case of assault was registered against Vinod Kumar, an ex-serviceman who is also serving a life term in the jail in the outskirts of Jammu. Kumar hails from Uttrakhand.
A high level enquiry has been ordered into the murderous attack on Sanaullah to be headed by a superintendent of police with two deputy superintendents in assistance.
The sources said the health condition of Sanaullah was stated to be very critical.
Sanaullah was arrested on April 1999 in connection with five cases related to terror activities. The attack occurred ahead of Sarabjit's funeral at his native village in Punjab.
Following the death of 49-year-old Sarabjit in Pakistan, the Union home ministry had issued advisories to all states to maintain high vigil in jails and ensure there was no attack on any Pakistani prisoner lodged there.
Excluding fishermen, there are nearly 220 Pakistani prisoners in Indian jails. A similar number of Indians are lodged in Pakistani jails.
With Agency Inputs
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