Islamabad, April 28 (IANS): The "latest chapter" in the story of Sarabjit Singh, an Indian national on death row in Pakistan, who was brutally beaten by other prison inmates, "is a sad one", a leading Pakistani daily said Sunday.

Sarabjit, 49, suffered critical head injuries in the assault by four to five prisoners with bricks and plates in Kot Lakhpat Jail in Lahore Friday.

He has been on death row in Pakistan since 1990 after being convicted by Pakistani courts for bomb blasts in Lahore and Multan, which left 14 people dead.

Sarabjit's family claims he is innocent, and that he crossed over to Pakistan in August 1990 in an inebriated state, and was arrested there.

The News International daily said the latest chapter in his story "has unfolded. And it is a sad one".

"The incident appears to be linked to the hanging of Afzal Guru in India early this year and apparent vengeance sought for this on a man who obviously had no role at all to play in that event," the daily said.

The daily lamented that it "should never have taken place at all".

It quoted his lawyer as saying that Sarabjit had been receiving threats for some time now.

"It is rather absurd that, despite these warnings, he could not be kept safe in jail. The suspension of prison staff for negligence, done soon after the incident, is not enough. A complete investigation is obviously required."

The daily hoped that "something concrete comes out" of an inquiry called by the top prison officer. "We need to get to the bottom of the matter."

Stating that similar acts of violence have been seen in Pakistan's prisons in the past, the daily said "action needs to be taken against those responsible"