LAHORE (AFP) - An Indian national facing the death penalty in Pakistan on espionage charges was rushed to hospital on Friday after suffering serious injuries in a clash with fellow prisoners, officials said.

Sarbajeet Singh was wounded in a quarrel with other prisoners on death row in Lahore's Kot Lakhpat Jail, provincial prisons chief Farooq Nazir said.

He gave no details, saying that an investigation had been ordered into the attack.

Singh, who was sentenced to death 16 years ago, has been admitted with "serious head injury", doctor Mohammad Ahsan from Jinnah Hospital told AFP.

"His condition is serious and he has been taken to the operation theatre," he added.

Singh was arrested following a bombing in the eastern Pakistani city of Lahore in the late 1990s in which 14 people were killed.

He was sentenced to death after being convicted by a Pakistani court on spying charges. His family has previously filed mercy petitions to Pakistani authorities seeking Singh's release.

Pakistan last year released an Indian man who had served three decades in a Pakistani jail on espionage charges.

Muslim-majority Pakistan and Hindu-majority India have fought three wars since the division of the subcontinent in 1947, two of them over the Himalayan region of Kashmir, which is divided between them and claimed by both.