Former prime minister Imran Khan has condemned the knife attack on Salman Rushdie, an India-born author and winner of the Booker Prize, saying the anger of Muslims against the author was understandable but it still didn't justify the attack, reported Guardian on Friday.

"I think it is terrible, sad," Imran told the newspaper in a comment on the violent attack that put Rushdie on a ventilator.

"Rushdie understood, because he came from a Muslim family. He knows the love, respect, reverence of a prophet that lives in our hearts. He knew that. So the anger I understood, but you can't justify what happened," the Pakistan Tehreek-e-Insaf (PTI) chairman was quoted by the newspaper as saying.

Rushdie, who was born in India to a Muslim Kashmiri family, has lived with a bounty on his head, and spent nine years in hiding under British police protection.

The author sustained severe injuries in the attack, including nerve damage in his arm, wounds to his liver, and the likely loss of an eye, his agent said. But his condition has been improving since the weekend, and he had been taken off the ventilator.