A high-level Iranian cleric has escalated the rhetoric against author Salman Rushdie, saying the 1989 fatwa calling for his killing cannot be revoked.

Ayatollah Ahmad Khatami, who has an influential post delivering the sermon on state radio during Friday worship, warned Britain it was defying the Islamic world by granting a knighthood to Rushdie.

"Awarding him means confronting 1.5 billion Muslims around the world," Khatami said. "In Islamic Iran, the revolutionary fatwa …is still alive and cannot be changed."

Thousands of worshippers at Tehran University chanted "Death to the English!" after he reminded them of the fatwa against Rushdie issued by the late Ayatollah Ruhollah Khomeini.

Khatami stopped short of calling for the fatwa to be carried out.

In 1989, Khomeini accused Rushdie of insulting Islam in his book The Satanic Verses, and called for him to be killed. The fatwa forced Rushdie into hiding for a decade.

The Queen'sdecision to knight Rushdie drew a complaint from the Iranian government and protests around the Muslim world.

There were rallies in several Pakistani cities on Friday, calling for Rushdie to be killed and for a boycott of trade with Britain.

In a rally in Karachi, Pakistan's largest city, a leader of the Jamiat Ulema-e-Islam party compared Rushdie's award to the cartoons of the Prophet Muhammad published last year in a Danish newspaper.

"Earlier they had published cartoons of our prophet, and now they have given an award to someone who deserves to be killed," Abdul Ghafoor Hayderi said.

In aMuslim area of Indian Kashmir, a strike over Rushdie'sknighthood closedshops, offices and schools.

Muslims also protested in London over thehonour, which Britain defended as fitting for one of the pre-eminent novelists of the 20th century.

Rushdie is author of Booker Prize-winning Midnight's Children and, more recently, Shalimar the Clown.

The fatwa against Rushdie was an irritant between Iran and Britain until 1998, when the Iranian government declared it would not support the fatwa but that it could not be rescinded.